e - drilling

8/10/2019 E - Drilling

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Drilling

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The drilling process.......................................... E3Drilling .................................................................. E3

Cutting data .......................................................... E4

Machining holes .................................................... E4

Cutting forces and power ....................................... E5

Chip control and cutting fluid .................................. E6

Drill selection procedure.................................. E7

Selecting drills ...................................................... E8

Drill diameter points to type of drill ......................... E9

Solid and brazed cemented carbide drills .............. E12

Indexable insert drills .......................................... E13

Application of drills ........................................ E14

Solid cemented carbide twist-drills ........................ E14

CoroDrill Delta C ................................................. E15

Recommendations for successful drilling .............. E16

Cutting fluid supply .............................................. E18

Cutting data ........................................................ E19

Maintenance ....................................................... E20

If problems should occur Delta C drills ............... E21

Wear definition Delta C ..................................... E24

Grades Delta C ................................................. E25

Cutting data Delta C ......................................... E26

Graphs for Delta C .............................................. E27

Machining recommendations ................................ E27

Tailor Made ......................................................... E28

Drill specifications Delta C ................................ E29

HardCut drill ....................................................... E33Brazed cemented carbide twist-drill ....................... E34

Coromant Delta ................................................... E34

Set-up recommendations ..................................... E35

Drilling with holder and houseing for

cutting fluid supply .............................................. E35

Cutting fluid volume compensator ......................... E36

Recommended maximum wear ............................. E36

Grades for Coromant Delta .................................. E37

Cutting data Coromant Delta ............................. E38

Graphs for Coromant Delta .................................. E39

Tailor Made ......................................................... E40

Contents

Chamfering insert for Coromant Delta ................... E41

Drill specifications Coromant Delta .................... E42

Indexable insert drills .......................................... E43

CoroDrill 880, Coromant U, T-Max U drills

and trepanning tools ........................................... E43

Application hints ................................................. E44

Cutting fluid ........................................................ E50

Insert wear ......................................................... E51

Application procedure for new operations ...............E52

Benefits of using a modern indexable insert drill .... E53

CoroDrill 880 ...................................................... E54

Tooling alternatives ............................................. E56

General information - CoroDrill 880 ....................... E56

Grades - CoroDrill 880 ......................................... E57

Specifications - CoroDrill 880 ............................... E58

Inserts - CoroDrill 880 ......................................... E59

Cutting data - CoroDrill 880 .................................. E60

Insert geometries Coromant U and T-Max U ........ E61

Cutting data Coromant U and T-Max U ................ E63

Graphs for Coromant U and T-Max U ..................... E65

Specifications Coromant U ................................ E66

Specifications T-Max U ...................................... E69

Varying the hole diameter rotating drill ............... E70

Radial adjustment for Coromant U ........................ E71

Tailor Made Coromant U .................................... E72

T-Max U stack drill ............................................... E73

Inserts - T-Max U stack drill .................................. E74

Graphs for T-Max U trepanning tool ....................... E75

Cutting data T-Max U trepanning ........................ E76Application hints T-Max U trepanning .................. E77

Holding instructions T-Max U ............................. E78

Coromant U step and chamfer drill ....................... E79

Tailor Made Coromant U step and chamfer ......... E80

Designation and formulas for drilling ..................... E82

If problems should occur indexable insert drills ... E84

Basic hints for successful drilling ......................... E86

Drilling


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The drilling process

Drilling

Drilling Trepanning Counterboring Reaming

Solid drillingis the most common drilling

method, where the hole is drilled in solid

material to a predetermined diameter

and in a single operation.

Trepanningis principally used for larger

hole diameters since this method is not

so power-consuming as solid drilling.The trepanning tool does not machine

the whole diameter, only a ring at the pe-

riphery. Instead of all the material being

removed in the form of chips, a core is

left round the centre of the hole conse-

quently, this method is for through-hole

applications.

Counterboringis the enlargement of an

exisiting hole with a specifically designed

tool. This machines away a substantial

amount of material at the periphery of

the hole.

Reamingis the finishing of an exisiting

hole. This method involves small work-

ing allowances to achieve high surface

finish and close tolerances.

Drilling ...... covers the methods of making cylin-

drical holes in a workpiece with metal

cutting tools. Drilling is associated with

subsequent machining operations such

as trepanning, counterboring, reaming

and boring. Common to all these proc-

esses is a main rotating movement com-

bined with a linear feed. There is a clear

distinction between short hole and deep

hole drilling, the latter being a special-

ist method for making holes that have

depths of many times (up to 150 times

the diameter see seperate catalogue.)

With the development of modern tools

for short hole drilling, the need for pre-

paratory and subsequent machining has

changed drastically. Modern tools have

led to solid drilling being carried out ina single operation, normally without any

previous machining of centre and pilot

holes. The hole quality is good, where

subsequent machining to improve the

measurement accuracy and surface tex-

ture is often unnecessary.

The drilling process can in some re-

spects be compared with turning and mill-

ing but the demands on chipbreaking and

the evacuation of chips is critical in drill-

ing. Machining is restricted by the hole

dimensions, the greater the hole depth,

the more demanding it is to control the

process and to remove the chips. Short

holes occur frequently on many compo-

nents and high material removal rate is

a growing priority along with quality and

reliability.


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Cutting dataThe cutting speed, or surface speed (vc)

in for drilling is determined by the periph-

ery speed and can be calculated from

the spindle speed (n) which is expressed

in number of revolutions per minute. Dur-

ing one revolution, the periphery of the

drill will describe a circle with a circum-ference of x Dc, where Dc is the tool

diameter. The cutting speed also var-

ies depending upon which cutting edge

across the drill-face is being considered.

A machining challenge for drilling tools

is that from the periphery to the centre

of the drill, the cutting speed declines in

value, to be zero at the centre. Recom-

mended cutting speeds are for the high-

est speed at the periphery.

The feed per revolution (n)in mm/rev

expresses the axial movement of the

tool during one revolution and is used to

calculate the penetration rate and to ex-

press the feed capability of the drill.

The penetration rateor feed speed (vf)

in mm/min is the feed of the tool in rela-tion to the workpiece expressed in length

per unit of time. This is also known as

the machine feed or table feed. The

product of feed per revolution and spin-

dle speed gives the rate at which the drill

penetrates the workpiece.

The hole depth (L)is an important factor

in drilling as is the radial cutting depth (ap)

and feed per tooth (fz)for calculations.

Machining holesHoles are either made or finish machined.

Most workpieces have at least one hole

and depending upon the function of the

hole, it needs machining to various limita-

tions. The main factors that characterize

a hole from a machining point of view are:

- diameter

- depth

- quality

- material

- conditions

- reliability

- productivity

Cutting speed, penetration rate, spindle speed and feed per revolution. Main hole-machining factors.

fn vf

vc

n HB

Ra

DL


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Cutting forces and powerTo produce a hole requires a certain

amount of energy. Cutting forces act on

the drill as it penetrates through the work-

piece removing metal and generating a

certain amount of power.

To start with, the power required in drill-ing varies with the type of workpiece

material when calculating how much is

required.

A specific cutting force for the material in

question also needs to be established.

The specific cutting forcevalue (kc)in N

per square-mm has been worked out and

tested for most materials and is avail-

able in a table relating to the effective

rake angle of the tool and the average

chip thickness. It is defined as the tan-

gential cutting force needed for a chip

with a certain cross-section (one square

mm) or the effective cutting force divided

by the theoretical chip area. Values are

indicated for a certain feed per tooth.

Steel normally has a specific cutting

force some three times that of non-fer-

rous alloys, and a HRSA has a value of

up to around twice that of steel.

In addition to the material factor, the

power (Pc)in kW required for a drilling

operation depends upon the diameter,feed rate and cutting speed. A formula is

indicated for calculating the approximate

power requirement for a certain operation

and this can then be checked to ensure

that the machine tool in question copes

with the application. Most holes with a

moderate diameter are no problem for

modern machines but for large diamters

with depths of several times the diam-

eter, it is wise to check the power.

Torque (Mc) in Nm is another value

which may be critical for some large-di-

ameter drilling operations, especially tre-

panning, as regards the total drilling mo-

ment that the drill is subjected to during

machining. The feed, diameter and mate-

rial are the main factors that affect the

torque value (see formula). The torque is

the sum of the moments on each cutting

edge and the product of the tangential

force and radius from the centre.

The feed force (Ff) in N is usually the

most important in driling from a perform-

ance point of view. This is the axial force

acting on the drill as it penetrates the

material. It needs to be considered in or-

der to ensure that the spindle power and

strength is sufficient for the drilling op-

eration. Applying an excessive feed force

can affect the hole quality, tool reliabil-

ity and stall the machine. On the other

hand, applying a sufficient feed force is

important for the cutting action and also

from producitivity point of view.

The feed force can be calculated fromthe provided formula and is related to

the diameter of the drill, feed and mate-

rial being drilled. The cutting edge an-

gleof the drill (r), of the cutting edges,also influences the feed force. The point

angle of the drill is ().

Feed force and torque.

Point angle and cutting edge angle.

r


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Chip control and cutting fluid ...... are important factors in drilling.

Generating suitable chip

forms and sizes and evacu-

ating them are vital to

the succes of any drill-

ing operation. Without

satisfactory perfor-mace in this regard,

all drills will rapidly

become ineffective

due to clogging up the

hole. Cutting speeds

and feeds are high with

modern drills but this has

only been made possible

through efficient evacuation of

chips with cutting fluid.

Most short hole drills have two chip chan-

nels through which the chips are evacu-

ated. With modern machines and drilling

tools, this is be done very effectively by

supplying cutting fluid internally through

the tool coolant holes. The cuting fluid is

ejected at the point of the drill during ma-

chining to lubricate the drill and flush out

chips throught the channels.

Chip information is influenced by the

workpiece material, tool geometry, cut-

ting speed, feed and to some extent the

choice of cutting fluid. Generally, increasedfeed and/or reduced cutting speed pro-

duces shorter chips. The chip length and

form can be said to be acceptable if the

chips can be flushed out reliably.

The rake angle (E) of the drill variesalong the cutting edge and decreas-

es from the periphery towards

the centre of the drill, such

as with solid and brazed

cemented carbide twist-

drills. Since the cutting

speed also drops fromthe periphery towards

the centre, the cutting

edge will work ineffec-

tively at the point of

the drill. As the point of

the drill presses and

scrapes the material rather

than cuts it, plastic deforma-

tion tends to occur where the rake

angle is negative and the cutting speed

low. This pressure gives rise to a relatively

high axial-force component. If the machine

is weak in relation to the size of hole to be

drilled, and the generated feed force, the

machine spindle may deflect and, as a re-

sult, oval holes may be produced.

Drilling with modern cemented carbide

drills enables high material removal

rates to be achieved and large volumes

of chips to be flushed out with cutting

fluid, supplied internally under high pres-

sure. The required pressure (Mpa) and

flow(l/min) are primarily dependent on

the hole diameter but are also affectedby the machining conditions and the

workpiece material.

When cutting fluid is supplied internally,

rotating drills require higher cutting fluid

pressure than non-rotating drills due to

the drop in pressure caused by the effect

of the centrifugal force. In order to avoid

having to compensate with very high

pressures on the cutting fluid supply, a

volume compensatorcan be used. But a

certain drop in pressure in the conduc-

tive system must also be taken into ac-

count for non-rotating drills and with ex-

ternal cutting fluid supply.

The pressure in the system should be

checked as well as the flow, so that thelatter is at least at the level which is rec-

ommended for the drill and that there is a

good margin at the tank.The cutting fluid

flow should be measured at the cutting

edge of the drill as this is where the rec-

ommended values apply. Minimum flow

and pressure values are recommended

relative to drill type and diameter.

Chip formation, chip evacuation and cutting fluid supply.

Rake angle of drill.

Suitable cutting fluid supply is critical in drilling.


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Drill selection procedure

Define your hole diameter, depthand quality requirementsConsider also production economy and

machining reliability aspects.

Select the type of drillChoose a drill for roughing and/or finishing

holes. Check that the drill is suitable for the

workpiece material, hole quality demands and

that it provides the best hole economy.

Choose the drill grade andgeometryIf an indexable insert drill has been selected,

inserts have to be selected seperately. Find

the right inserts for the drill diameter and

choose recommended geometry and grades

for the workpiece material. For solid or brazed

cemented carbide drills, select suitable grade.

Select the shank styleMany drills are available with different mount-

ing options. Find the style compatible with the

machine.

Coromant Capto integrated drill.


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Selecting drills

Modern cemented carbide drilling tools

are very efficient and have come a long

way from out-dated, high speed twist-

drills - which are still in use in many ma-

chine shops. As a consequence, the cost

per machined hole has fallen dramati-cally. For solid cemented carbide drills,

tool-life is around 20 times better than

for HSS and the cutting speed capacity

several times higher with the same feed

rate. The basic concept of the twist-drill

as such is still with us but in a very re-

fined form. The drill-point geometries

used today have vastly improved the cut-

ting action of the conventional chisel-

edge and tool materials have lifted per-

formance and extended tool-life.

Solid carbide and brazed twist-drills drill

operate at lower cutting speeds/higher

feeds in relation to machine and opera-

tion while indexable insert drills use high

cutting speeds/low feeds.

The modern cemented carbide twist-

drillsare application orienated towards

above all two directions:

- precision holes, giving closer toleranc-

es and surface finishes than indexable

insert drills

- smaller diameter holes, where the in-

dexable inserts drills are not a practical

solution.

The solid cemented carbide twist-drill

range of Coromant Delta-C covers diam-

eters from 1.5 to 20 mm.

The brazed cemented carbide twist-drill

Coromant Delta covers diameters from

9.5 to 30.4 mm.

Hole tolerances for these drills can be

within IT8 and finishes within Ra 1 mi-

cron depending upon drill length, tool

holding and conditions. The drill shank

tolerance is h6. Cemented carbide grade

options are available for all materials,

including TwinGrade compound grade

for stainless steel drilling. Two different

grades are sintered together to provide

high speed capability for the periphery

and low speed capability for the centre

of the tool.

Thanks to the high bending stiffness of

cemented carbide, it is possible to apply

tool lengths of 8 times the diameter in

stable conditions (Tailor Made) and 12

to 14 times as specials.

The cemented carbide indexable insert

drillprovides high machining productiv-

ity, versatility and long, reliable tool-life.

Todays drills are not just fast roughing

drills. They are capable of making holes

even more rapidly than the first genera-

tions of these drills but they are also ca-

pable of finishing holes to a better level

and keeping within closer tolerances

than previously, not just from the solid

drilling operation but also from boring

and the Wiper insert technology.

The indexable insert drills CoroDrill 880.

Coromant U-drill and T-Max U(includ-

ing the trepanning tool version)

cover the diameter range 12 to

110 mm as standard.

The achievable hole toleranc-

es with the new CoroDrill 880

drill have been almost halved to

+ 0.25 mm and with a moderate

feed, the surface finish possible is

Ra 0.5 micron.

Production economy has been

improved considerably with

the new CoroDrill 880 where

penetration rates are up to twice

as high.

Cemented carbide drills.

Coromant Delta C

Coromant Delta

CoroDrill 880


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One of the first things to be established

when choosing a hole-making tool is

whether an indexable insert drill or a

regrindable drill should be used. The

diameter of the hole is the first factor.

Indexable insert drills cannot be used forsmall diameter holes (smaller than 12

mm) so these applications need solid or

brazed cemented carbide drills.

Small-diameter holes

Solid cemented carbide drills, such as

the CoroDrill Delta C, are available in

different versions, covering a diameter

range from 0.3 to 20 mm.

Where it is possible to machine at high

spindle speeds the properties of cement-

ed carbide should be utilized in order to

achieve increased productivity. When the

stability of the set-up is really poor, to the

extent that it puts the relaibility of the

carbide drill at risk, a high speed steel

drill can be an alternative choice.

When the diameter of the hole is within

the range covered by both CoroDrill Delta C

and Coromant Delta, the latter a brazed

carbide drill may often be the best

choice. Coromant Delta offers closer tol-

erances with respect to both size and

surface finish, low cutting forces and

high cutting data in the ISO K area.

Medium-sized hole diameters

The diameter range designated as medi-

um sized hole diameters is the range in

which indexable insert drills and brazed

carbide drills (Coromant Delta) overlap.

When close tolerances are required,

and/or the hole depth restricts the use

of indexable insert drills, then Coromant

Delta is usually the best choice. With the

introduction of CoroDrill 880, however,

the borderline has shifted with indexableinsert drills now having the capability of

a finishing tool.

When the initial penetration surface is

not flat, or the hole is predrilled or cross

drilling has to be undertaken, then index-

able insert drills are often the only op-

tion. These will provide the lowest cost

per machined component, since there

are inserts that can be changed and no

regrinds. This cost advantage should be

particularly noted when machining large

volumes of components.

Drill diameter points to type of drill

Large-diameter holes

Only indexable insert drills are available

for what is designated here as large di-

ameter holes and the choice of tool is

primarily concerned with choosing the in-

sert geometry and grade. When the ma-chine power is limited, trepanning drills

are used instead of solid drills.

The combination of insert geometry/

grade is established between the periph-

eral insert and central insert to provide

optimal performance.

Very large diameter indexable insert drills

with several cartridges have peripheral

inserts, internal peripheral inserts, cen-

tre inserts and internal centre inserts.

Solid carbide drills to indexable insert trepanning tools cover hole diameters from 0.3 to 110 mm for short

hole drilling.


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NHS

KMP

Dc1.5 20.00 mm Dc5.00 14.00 mm Dc3.00 16.00 mm Dc9.50 30.40 mm

CoroDrill

Delta C

Coromant

Delta

Drill depth

Material

Hole tolerance IT8-10 IT8-10 IT8-10

Surface finish Ra

2 5 Dc

2 7 Dc

2 3 Dc

3.5 5 Dc

??? ??? ???

?

??

?

???

???

?

?

Step & chamfer

Versatility

Step / chamfer

Chamfer

14 m12 m12 m

NH

KMP

NHS

KMP

??

??

P K N N

*) By presetting.

??? = Very good

?? = Good

? = Fair

Steel Surface with angle

Cross hole

Plunge drilling

Stainless steel

Cast iron

Aluminium

Super alloys

Hardened steel

Radial adjustment

Stackdrilling

Trepanning

Material

N

H

S

K

M

P

CoroDrill

880

Dc14 29.5 mm

2 4 Dc

15 m

???

???

???

???

?

???

???

NHS

KMP

R840 R850 R841 R411.5

General

drilling


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Dc12.7 58 mm

IT13IT11 *)

2 5 Dc

Coromant U

15 m

NHS

KMP

Dc1/Dc2/Dc312.7 58.9 mm

IT13

IT11 *)

0.2 0.2

2.3 Dc

Coromant U

Step & chamfer

Dc27 59 mm Dc60 80 mm Dc60 110 mm

T-MAX U

stackdrillSolid

T-MAX U 60 mm

27 m15 m 27 m 27 m

2.5 Dc

2.5 Dc

2.5 Dc

Trepanning

*) By presetting.

0.2

NH NHS

KMP

S

KMP

NHS

KMP

NHS

KMP

Hardened steel

= Very good

= Good

= Fair

Steel

Stainless steel

Cast iron

Aluminium

Super alloysBoring

Material

Chamfer drilling

Step drilling

N

H

S

K

M

P

Plunge drill

0.20

Dc12.7 35 mm

15 m

4 Dc

NHS

KMP

R416.2 R416.21 R416.01 R416.9 R416.7 R416.22


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Solid and Brazed cemented carbide drills

CoroDrill Delta-C drill R840 GC1220

Diameter range 0.5 20.00 mm

Drill depth 2-7 x D

Cyl./WN shanks

First choice in general drilling

Tailor made options

Hard Cut drill HC 2...6


Drill depth 5 x D

Cylindrical shank

For removal of broken taps or drilling in difficult materials

PMKNSH

CoroDrill Delta-C chamfer drill R841 GC 1220


Drill depth 2-3 x D

Cyl. Shank

Drill & chamfer

Tailor made options

PMKNSH

CoroDrill Delta-C drill R850 N20D


Drill depth 2-7 x D

Cylindrical shank

Unique geometry specially designed for drilling Aluminium

Tailor Made options

N

CoroDrill Delta-C drill R842 GC1210

Diameter range 3.0 16.0 mm Drill depth 5 x D

Cylindrical shank

K

Coromant Delta drill R411.5 P20/K20


Drill depth 2-5 x D

Cylindrical with flat/CWN shanks

Superior hole tolerance and surface finish

Suitable for unstable conditions

Tailor made options

PMKN (S) H

H


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T-Max U 60 mm drill

Exchangeable cartridges

Diameter range 60 80 mm

Drill depth 2.5 x diameter

T-Max U stack drill

Problem solver for drilling stacked components

Diameter range 27 59 mm


Coromant Whistle Notch shank

T-Max U trepanning drill

Suitable when machine power is a limitation for solid drilling

Exchangeable cartridges

mm011revoretemaidllird,mm01106egnarretemaiD

available on request


dekcatsgnillirdrofdesuebnacegdirtracrennilaicepS

components

Coromant U drill R416.2

Diameter range 12.7 58 mm

Drill depth 2 4 x diameter

Different shank types

Coromant U drill, step and chamfer

Available as Tailor Made


Three tools in one


T-Max U Left hand drill



Coromant Whistle Notch shank

Coromant U Socket head cap screw drill

Standard diameter for screw sizes M12. M14. M16 and M20

Drill depth 2 x D

Cylindrical shank with flat (ISO 9766)

Coromant U Plunge drill

Suitable for rough opening of deeper cavities

Diameter 12.7 35 mm

Drill depth 4 x D

Cylindrical shank with flat (ISO 9766)

retemaidsnoitpolaicepsdereenignE

range 12.7 58 mm, 2 6 xD

Indexable insert drills

CoroDrill 880

Diameter range 20 29.5 mm

Drill depth 2 4 x Dc



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Application of drills

CoroDrill Delta-CR840: first choice for general drilling

(1.5 20 mm diameters)

R850: for drilling in aluminium

(5 14 mm diameters)

R841: for step and chamfer options

(3 16 mm diameters)

Hole depths: up to 7 times the drill

diameter, depending on type andapplication

Workpiece materials: all types (R850

for Al)

Hole tolerance achievable: up to IT8

Surface finish achievable: up to Ra 1

micron

Solid cementedcarbide twist-drills


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Recommendations for successful drilling CoroDrill Delta-C

Maximum stabilitythroughout the entire

system of spindle, tool holding and drill

is essential. Instability puts heavy de-

mands on the rigidity of the entire tool

system. Solid carbide is the stiffest pos-

sible tool material and, more than any

other type of drill, is capable of high

speed production of high-quality holes.

However, when machining conditions are

unstable or there are tough demands on

the tool, precautions should be taken or

an alternative considered. To fully make

use of Coromant Delta-C drill capabili-

ties, the machine tool should be rigid, in

good condition and work piece clamping

should be secure.

Vibration, even at a very low frequency,

has a negative effect on tool-life and pro-

duction security, in that cutting edges

may develop chipping rather than flank

wear and thus generate poor finish and

rapid breakdown. Good quality torque

transmision and coolant supply are also

success factors.

TIR

Good tool holding is the basis for good performance in drilling.

A rotating drill is preferred. However, if

using the drills stationary, such as on a

lathe, the centre of the drill should be

checked to make sure it is aligned with

the centre of the spindle.

In the case of application on special-pur-

pose machines the use of bushings is

not recommend.

Minimum tool run-out is essential in

drilling.One of the main criteria for suc-

cessful use of solid carbide drills is low-

est possible run-out. It is recommended

not to exceed a maximum TIR (Total Indi-

cator Readout) of 20 microns for the drilland chuck in order to achieve the possi-

ble hole tolerance within down to IT8 and

also to achieve the best tool-life.

The nominal runout of the drill, in rela-

tion to the shank (measured in a V-block),

should not exceed 0.015 mm for the to-

tal length of the drill.

The smallest total runout is provided

by the CoroGrip power chuck with a

Coromant Capto coupling and also with

shrink fit holding tools.


16/90

E 16

Drilling

A

B

C

D

E

F

G

H

Deeper holes with external coolant supply.Usually drilling of a hole can

be performed in one single step. But if deep holes are drilled (more than

3 x D), using external fluid supply, one third of the depth can be drilled

continuously followed by a peck drilling cycle. But peck drilling of deep

holes should be problem solver only.

Peck drilling cycle:After drilling one third of the depth, the drill is lifted

sufficient for chip evacuation, cleaning of the hole and then followed byrepeated drilling cycles.

Drilling of non-flat surfaces.Drilling of component surfaces inclined to a

maximum of 10 is acceptable but a reduction of feed is essential on

entry to prevent drill sliding, and, when the drill exits, to prevent wear on

circular land or even drill breakage.

Inclination smaller than 5:cutting action is intermittent. The feed should

be reduced to 1/3 of normal feed rate until cutting full diameter.

Through-holes:when exiting through-holes the feed must be reduced to

1/3 of normal feed.

Inclination of 510:start by performing a centering operation with a

short drill with the same point angle. Alternatively, mill a small flat.

Inclination larger than 10:drilling is not possible unless the entry sur-

face is prepared.


17/90

E 17

Drilling

A

B

C

D

E

F

G

H

Irregular surfaces:when entering, the feed must be reduced to a quarter

normal rate in order to avoid chipping.

Concave surfaces:are possible to drill if the radius is larger than 15

times the drill diameter. The feed should be reduced to a third of normal

rate when entering.

Convex surfaces:are possible to drill if the radius is larger than 4 times

the drill diameter and the hole is perpendicular to the radius. The feed

should be reduced to a half of normal rate when entering.

Cross-hole drilling:can be made if the feed is reduced to a quarter of nor-

mal rate when entering and exiting the cross hole.

Stack drilling: drilling of more than one workpiece-plate at a time is possi-

ble with full feed providing the following measures are taken:

- good clamping of the plates, especially since plates are generally not per-

fectly flat. A common practise is to put industrial paper (thickness approx.

0.51 mm) between the plates. This levels out irregularities and dampens

vibrations.

A further benefit for including paper is to keep the chips in place and also

to protect the drill from being damaged by the end disc, formed at the exit

of each plate. If possible, the plates should also be secured and clamped

in the centre before drilling starts.

Enlarging holes: Counterboring operations are not possible with

Coromant Delta-C drills.


18/90

E 18

Drilling

A

B

C

D

E

F

G

H

Cutting fluid supplyThe cutting fluid supply

when drilling with Delta-C is

an important factor for suc-

cessful performance. Chip

evacuation and lubrication

between drill and hole wall

are primary functions whichhave to be supported.

Nominal and minimum val-

ues for cutting fluid pres-

sure and volume are shown

in diagrams.

These values are a guide

and may need adjustment

depending on the machin-

ing conditions.

Cutting fluid for Coromant

Delta-C drills in order to

achieve a good machining re-

sult a soluble oil with EP ad-

ditives should be used, but in

certain applications neat oil

could give a better result. If a

soluble oil is used, it should

contain at least 10 - 12%

oil for max. tool life.

When drilling in high alloy, hard or stain-

less steels, a better result is obtained

with richer soluble (25% oil) or neat cut-

ting oils. A richer mixture can result in

longer drill life combined with better hole

tolerances and surface finish.

With an external cutting fluidsupply, im-

proper chip evacuation can occur if the

cutting fluid nozzle is not properly direct-

ed onto the periphery of the tool in linewith the flute spiral. This condition can

lead to blue or brown chips, undersized

holes, drill breakage or wear on the guid-

ing chamfers of the drill.

To optimize chip evacuation, at least one

cutting fluid jet (two if drill is stationary)

must be directed at a slight an-

gle to the tool axis.

Smaller diameter drills need

higher pressure than larger

drills, because the fluid volume

going through is less. The cut-

ting fluid pressure will be critical

for smooth chip evacuation par-

ticularly at high speeds. Internal

cutting fluid supply is always pre-

ferred.

External supply is also acceptable

and can help to avoid built-up edge

formation. In some situations drilling

with mist cutting fluid gives improve-

ments at high surface speeds.

Delta-C drills are available in versions

designed for internal as well as external

cutting fluid supply.

Volume Pressure

Coromant Delta-C drills for aluminium machining.

5

4

3

2

1

5 10 15 20 Dcmm

3xD 5xD0.6 1.0

0.5 0.8

0.4 0.6

0.3 0.4

5 10 15 20 Dcmm


19/90

E 19

Drilling

A

B

C

D

E

F

G

H

Cutting dataEffects of cutting speed:

the main factor in determining tool-life

affects power consumption

Excessive cutting speed can lead to:

rapid flank wear on drill

plastic deformation of cutting edges poor hole quality

out of tolerance

Cutting speed too low:

built-up edge formation on drill

negatively affect chip evacuation

poor productivity/high cost per hole

Effects of feed rate:

decisive for chip formation

affects power consumption

contributes to mechanical and thermal

stress

High feed rate leads to:

good chip control

less time in cut

less tool wear

higher risk of drill breakage

hole quality can deteriorate

Low feed rate leads to:

longer chips

quality improvement

accelerated tool wear longer time in cut/higher cost per hole

Importance of chip control:

Poor chip control can lead to unsatisfac-

tory hole-finishes and possible breakage

of the Delta-C drill.


20/90

E 20

Drilling

A

B

C

D

E

F

G

H

MaintenanceA collet and tool shank in bad condition

will ruin an otherwise accurate setup.

When using a collet chuck, it must be care-

fully checked that the collet and the tool

shank - are in good condition, and from

burrs and dirt. Old collets lose their pre-

cision very quickly. Confirm that TIR (Total

Indicator Readout) is within 20 microns

(m). An unacceptable run-out can be tem-porarily reduced by turning the drill or the

collet 90 or 180 to find lowest TIR.

Whistle Notch and collet chucks can give

rise to a run-out of 40 microns which

must be improved on to achieve an ac-

ceptable result.

Consistent and accurate clamping of

the tool shank is always achieved in

a CoroGrip power chuck. If collets are

required their run-out is up to 23 mi-

crons only.

Tool-life ensuring a long predicatable

one by:

a rigid set-up will improve tool-life

For best performance in demanding op-

erations, the Delta-C should be clamped

in a rigid, high precision chuck.

Recommended is the hydromechanical

power chucks CoroGrip and Hydrogrip as

they provide the highest torque transmis-

sion and the lowest run-out on the mar-ket. Other suitable holding tools include

shrink fit and hydraulic chucks.

Between 5-10 times extra life by

regrinding and recoating

A Delta-C drill can be reground. However,

it is important to follow the specific in-

structions so that the original Delta-C ge-

ometry is retained and accordingly the

performance. For reconditioning to re-

tain the original tool geometry, the wearbefore regrinding must not exceed the

maximum indicated in the recommen-

dations. Since the coating disappears

when regrinding the flank, resistance to

wear will be reduced and recoating is

therefore recommended.

Coromant Delta-C drills can be reground according to specific instructions.

Good quality chucks are vital for accurate.

Collet practice:

use sealed collets in combination with internal cutting

fluid supply.

carry out collet and tool maintenance frequently.

replace worn and damaged collets with new ones.


21/90

E 21

Drilling

A

B

C

D

E

F

G

H

Built up edge

1. Too low cutting speed and edge

temperature2. Too large neg. land

3. No coating

4. Too low percentage of oil in the cut-

ting fluid

1. Increase cutting speed or use exter-

nal cutting fluid2. Sharper cutting edge

3. Coating on the edge

4. Increase the percentage of oil in the

cutting fluid

Chipping on the cutting edge

corner

1. Unstable fixturing

2. TIR too large

3. Intermittent cutting

4. Insufficient cutting fluid (Thermal

cracking)

5. Unstable toolholding

1. Check fixture

2. Check radial run-out

3. Lower the feed

4. Check cutting fluid supply

5. Check the toolholder

Problem Cause Solution

How to identify and rectify tool problems when drilling with Delta-C drills.

Large wear on the cutting edge

1. Cutting speed too high

2. Feed too low

3. Grade too soft

4. Lack of cutting fluid

1. Lower the cutting speed

2. Increase the feed

3. Change to a harder grade

4. Check for proper cutting fluid supply

Chipping on the cutting edges

1. Unstable conditions

2. Maximum allowed wear exceeded.

3. Grade too hard

1. TIR too large

2. Cutting fluid too weak

3. Cutting speed too high

4. Abrasive material

1. Check the setup

2. Replace drill sooner

3. Change to softer grade

1. Check the radial runout

2. Use neat oil or stronger emulsion

3. Lower cutting speed

4. Change to harder grade

Wear on the circular lands

If problems should occur Delta-C drills


22/90

E 22

Drilling

A

B

C

D

E

F

G

H

Wear on the chisel edge

1. Cutting speed too low

2. Feed too high

3. Chisel edge too small

1. Increase cutting speed

2. Lower feed

3. Check dimensions

1. Cutting speed or/and feed too high

2. Not enough cutting fluid supply3. Unsuitable drill/grade

1. Lower the cutting speed or/and feed

2. Increase cutting fluid pressure andvolume

3. Use a harder grade

Excessive wear due to plastic

deformation

Drill breakage

1. Insufficient clamping

2. Workpiece is moving

3. Unsuitable cutting conditions

4. Insufficient spindle power

5. Chip jamming

6. Feed too high

7. Excessive wear

1. Stabilize workpiece and drill

2. Improve clamping

3. Check cutting data

4. Check machine

5. Adjust cutting data/fluid supply

6. Lower the feed

7. Check wear more frequently

Thermal cracks (Notches)

1. Inconsistent cutting fluid 1. Check cutting fluid supply

2. Fill cutting fluid tank



23/90

E 23

Drilling

A

B

C

D

E

F

G

H

How to identify and rectify workpiece errors when drilling with Delta-C drills.

Hole off centre

1. Unstable conditions drill/workpiece

2. TIR too large

3. Drilling against inclined surface

4. Non-symmetrical edges (reground)

5. Feed too high

1. Improve workpiece clamping

2. Improve TIR

3. Spot drill surface

4. Check regrinding geometry

5. Reduce feedrate

1. Feed too high

2. Drill is worn out

3. The negative land on the cutting

edge too wide

4. Too sharp an outer diameter corner

1. Lower the feed

2. Change drill more often

3. Smaller negative land width

4. Use corner chamfer or radius

Burr on exit side

1. Unstable conditions

2. Too large TIR

3. Not enough or weak cutting fluid

supply (volume or pressure)

4. Chip jamming

5. Feed too high

1. Improve clamping of workpiece/drill

2. Improve TIR

3. Check cutting fluid supply

4. Adjust cutting data/cutting fluid

supply

5. Reduce feed

Hole is too big

1. Unsuitable cutting conditions

2. Poor toolholding of drill/workpiece

3. Non symmetrical geometry

4. Too large TIR

1. Increase speed, reduce feed

2. Check holding and clamping

3. Check regrinding

4. Improve TIR


Ra

Bad surface finish


24/90

E 24

Drilling

A

B

C

D

E

F

G

H

FlankDrillcentreZone

Circular landFace

1 2 3 1 2 33.00 - 6.00 0.20 0.20 0.20 0.20 0.20 0.20

6.01 - 10.00 0.20 0.20 0.25 0.25 0.25 0.25

10.01 - 14.00 0.25 0.25 0.25 0.30 0.30 0.30

14.01 - 17.00 0.25 0.25 0.30 0.30 0.30 0.30

17.01 - 20.00 0.30 0.30 0.35 0.35 0.35 0.35

Drill diameter

Dcmm

Flank wear

VBmm

Crater wear

KBmm

Zone Zone

Wear definitionCoromant Delta-C

In ISO K-materials, performance can be improved by adding

corner chamfers to the drill 0.54.0 mm x (20-45). In ISO H-

materials, a corner radius can be added to slow down the wear

rate. r= 0.2Dc/10 mm.


25/90

E 25

Drilling

A

B

C

D

E

F

G

H

Balinit A

TiN general purpose coating for most drilling applications.

Most recoaters supply this type of coating. Delta drill P20 and

K20 has this coating.

Application: Steel, C.I., non-ferrous materials.

Balinit B

TiCN general coating for harder materials giving higher edge

temperature.

Application: Harder steel, harder C.I. up to 300 HB.

Coromant bronze

TiN/TiAlN. A more tough coating compared to Futura Nano.Also better adherence to the substrate and improved resist-

ance to crater wear compared to Futura Nano. Grade 1220

has this coating.

Application: Most materials including ISO H, S and N-types.

Balinit G

TiCN + TiN. General coating for most materials..

Application: Steel, C.I., stainless, HRSA, hard materials, non-

ferrous materials.

Futura Nano

Balinit TiAlN. General coating for harder steels 35-55 Rc.

Good abrasive wear resistance and medium toughness. Allows

higher speeds and dry/semi-dry conditions.

Application: Steel, stainless, C.I., non-ferrous, HRSA and

titanium.

Futura Top

Balinit TiAlN. General coating with good abrasive wear resist-

ance and medium toughness. Very smooth surface finish

giving low adherence from work material on the cutting edge.

Recommended for R850-Al drill.

Application: Steel, stainless, C.I., non-ferrous, HRSA andtitanium.

HardLube

Balinit TiAlN + WC/C. "Low friction" coating, promotes good

chip evacuation and temperature control.

Application: Low carbon steel, HRSA-material, cobalt-chrome.

Difficult to machine materials. Problem solver.

Grades for CoroDrill Delta-C

P

Steel

M

Stainlesss

teel

01

10

20

30

40

50

GC1210

GC1220

GC1220

Wear resistance

Toughness

Good

Averageconditions

Difficult

GC1220

GC1210

GC1220

GCN20D

GC1220

K

Castiron

N

Aluminium/

Non-ferrous

S

Heatresistantan

dtitanium

alloys

H

Hardenedma

terials GC

1220

PVD-coatings for CoroDrill Delta-C available as Tailor Made


26/90

E 26

Drilling

A

B

C

D

E

F

G

H

Cutting data CoroDrill Delta-C R840/841/850/415.5

1) Internal cutting fluid supply is recommended when drilling stainless steel as a good

supply of coolant at the cutting edges is essential for chip evacuation and tool life.

2) Rm = ultimate tensile strength measured in MPa.

3) Higher feeds should be used in stable and favourable machining conditions.

Unalloyed steel

P 01.0 125 C = 0.05-0.10% 1220 80-140 0.10-0.25 0.15-0.34 0.20-0.40 0.22-0.4501.1 125 C = 0.10-0.25% 1220 80-140 0.10-0.25 0.15-0.34 0.20-0.40 0.22-0.4501.2 150 C = 0.25-0.55% 1220 80-140 0.10-0.25 0.15-0.34 0.20-0.40 0.22-0.45

01.3 170 C = 0.55-0.80% 1220 70-130 0.10-0.25 0.15-0.34 0.20-0.40 0.22-0.45

01.4 210 1220 70-120 0.10-0.25 0.15-0.34 0.20-0.40 0.22-0.45

02.1 180 1220 70-120 0.10-0.20 0.14-0.30 018-0.35 0.20-0.4002.2 275 1220 70-100 0.10-0.20 0.14-0.30 018-0.35 0.20-0.4002.2 350 1220 50-80 0.10-0.20 0.14-0.25 018-0.35 0.20-0.38

03.11 200 1220 40-80 0.08-0.14 0.10-0.22 0.14-0.25 0.16-0.3203.21 325 1220 40-70 0.08-0.14 0.10-0.22 0.12-0.25 0.18-0.28

06.1 180 1220 70-130 0.10-0.20 0.15-0.34 0.20-0.40 0.22-0.4506.2 200 1220 70-120 0.10-0.20 0.15-0.34 0.20-0.40 0.22-0.45

Feed fnmm/r 3)

Drill diameter, mmMaterial

Carbon tool steel

Stainless steel

Cuttingspeed v

c

m/min

CMCNo

NewCoromantgrade

M

S

K

H

N

HB

3.006.00 6.0110.00 10.0114.00 14.01-20.00

05.11 200 1220 40-801) 0.08-0.14 0.08-0.20 0.12-0.22 0.14-0.241030 35-601) 0.08-0.14 0.10-0.22 0.14-0.28 0.16-0.30

05.21 180 1220 40-801) 0.08-0.14 0.08-0.20 0.12-0.22 0.14-0.241030 35-601) 0.08-0.14 0.10-0.22 0.14-0.28 0.16-0.30

15.21 200 1220 40-801) 0.08-0.14 0.08-0.20 0.12-0.22 0.14-0.241030 35-60 0.08-0.14 0.10-0.22 0.14-0.28 0.16-0.30

20.21 250 1220 10-25 0.06-0.12 0.08-0.15 0.08-0.15 0.10-0.1620.22 350 1220 10-25 0.06-0.12 0.08-0.15 0.08-0.15 0.10-0.1620.24 320 1220 10-25 0.06-0.12 0.08-0.15 0.08-0.15 0.10-0.16

23.21 Rm 2)= 850 1220 20-60 0.06-0.12 0.08-0.20 0.14-0.28 0.16-0.3023.22 Rm 2)=1050 1220 20-60 0.06-0.12 0.08-0.20 0.14-0.28 0.16-0.30

07.1 130 1220 90-150 0.15-0.30 0.25-0.40 0.35-0.60 0.40-0.6007.2 230 1220 70-130 0.15-0.25 0.20-0.35 0.30-0.55 0.35-0.55

08.1 180 1220 90-150 0.15-0.30 0.25-0.40 0.35-0.60 0.40-0.6008.2 260 1220 70-130 0.15-0.25 0.20-0.35 0.30-0.55 0.35-0.55

09.1 160 1220 80-110 0.15-0.30 0.25-0.40 0.35-0.60 0.40-0.6009.2 250 1220 70-100 0.15-0.25 0.20-0.35 0.30-0.55 0.35-0.55

04.1 43-47 HRc 1220 30-50 0.06-0.10 0.08-0.12 0.10-0.15 0.12-0.1804.1 47-60 HRc 1220 15-25 0.06-0.10 0.08-0.12 0.10-0.15 0.12-0.18

30.11 60 1220/N20D 120-230 0.15-0.25* 0.20-0.40* 0.30-0.50* 0.40-0.60*30.21 75 1220/N20D 120-230 0.15-0.25* 0.20-0.40* 0.30-0.50* 0.40-0.60*

33.1 110 1220/N20D 90-150 0.15-0.25* 0.20-0.40* 0.30-0.50* 0.40-0.60*

33.2 90 1220/N20D 90-150 0.15-0.25* 0.20-0.40* 0.30-0.50* 0.40-0.60*

High carbon steel

Low alloy steel

High alloy steel

Steel castings

Non-hardened / Ferritic/Martensitic

Austenitic

Stainless steelAustenitic castings

Heat resistant super alloys Nickel base

Annealed or solution treatedAged or solution treated and agedCast or cast and aged

Titanium alloys

, near and + alloys, annealed+ alloys in aged conditions, alloys,annealed or aged

Malleable cast iron

Ferritic (short chipping)Pearlitic (long chipping)

Grey cast iron

Low tensile strengthHigh tensile strength

Nodular cast iron, SG iron

FerriticPearlitic

Extra hard steel

Hardened and tempered

Aluminium alloysWrought or wrought andcoldworked, non aging

Cast, non-aging

Copper and copper alloys

Free cutting alloys, 1% Pb

Brass, leaded bronzes, 1% Pb

Non-hardenedHardened and temperedHardened and tempered

AnnealedHardened tool steel

UnalloyedLow-alloy (alloying elements


27/90

E 27

Drilling

A

B

C

D

E

F

G

H

Graphs for Corodrill Delta-C R841, R840 and R850

Net power

Feed force

Machining recommendations

Stainless SteelFor these applications grade GC1220 in drill type R840 with

internal coolant supply is the first choice. Use high feed rate.

If chip control is difficult to obtain with recommended cutting

data, reduce the the feed towards minimum value.

Use the highest coolant pressure/quantity available. Rich mix-

ture will improve performance.

SteelFirst choice in general steel material is type R840 grade 1220.

Drills with both internal and external coolant supply is available.

Also possible to drill in hardened steel up to 60 HRC with this

grade. When drilling hard material material use shortest pos-

sible flute length.

Note that only net power ratings are given. Allowance must be

made for the efficiency of the machine and the cutting edge

wear.

The graphs show nominal values which should not be regarded

as strict recommendations. The values may need adjusting de-

pending on the machining conditions e.g., the type of material.

AluminiumFirst choice is type R850 in grade N20D recommended to run

with high cutting data in Si Aluminium of below 12%. High pen-

etration rate possible with minimal burr formation on both enter

and exit side of hole.

Drill diameter

Ff

[kN]

5

4

3

2

1

0

0 2 4 6 8 10 12 14 16 18 20 Dc[mm]

Ff= 0.5 Dc fn kcfz sinr [N] 2

Drill diameter

Pc

[kW]

5

4

3

2

1

0

0 2 4 6 8 10 12 14 16 18 20 Dc[mm]

Pc=

Dc fn kcfz vc

[kW] 240 x 103

Cutting fluid flow

Drill diameter

Min

5 10 15 20 Dc[mm]

l/minq

10

9

8

7

6

5

4


28/90

E 28

Drilling

A

B

C

D

E

F

G

H

Dc1

l4

l4a

l21

l2

Dc2

ch

pa1pa2

pa3l4b

dmmD21

CoroDrill Delta-C R840 with cylindrical and Whistle Notch shanks

Corner Mod.1 = Standard type with special diameter and length, D

c1= 3.020.0 mm

4 = Step drill, Dc1

= 3.016.0 mm

5 = Chamfer drill with 2 steps and extended shank, Dc1

= 3.016.0 mm

CYLWN

CYL WN

CYL WN

CYL WN

CYL WN

2 = Chamfer drill with extended shank, Dc1

= 3.016.0 mm

3 = Standard type with extended shank, Dc1

= 3.020.0 mm

Shank type

Coolant supply

Further drill-variation possibilities to optimize machining are available as special tools.

Internal

External

Cylindrical CYL

Whistle Notch WN

Options

Drill type

Carbide grade

Tolerance

Tolerance

Mounting

type

Coolant supply

Coating type,

(modified)

Helix angle

(type 1)

Back taper

Circular land

Corner Mod.

Corner radius rCorner chamfer

Diameter 3.020.0 mm

1. 3 Dc1 = 3.020.0 mm/2. 4. 5 D

c1 = 3.016.0 mm

GC1220 or modified

Tolerance on Dc1 = h7/js7/m7 for drill type 1, 2, 3, and

h8/js8/m8 for drill type 4, 5

Drill depth mm Type 1 3.0118.5, type 2 3.080. type

3 3.0118.5

Drill depth Type 4 3.064 mm


Reach length 9.7155 mm

Overall length 49.7205 mm

Step diameter 3.520 mm, for d rill type 4


Chamfer width 0.52 mm, for drill type 2, 5

Tolerance on Dc2 = h7/js7/m7. for drill type 4, 5

Point angle = 118150

Chamfer angle = 60150, for type 2

Step angle = 60180, for type 4, 5

Step angle = 60150, for type 5

Step length = 5.2120 mm, for type 4

Step length = 8108 mm, for type 5

Cylindrical shank CYL,

Whistle Notch shank WN

Mounting size 6, 8, 10, 12, 14, 16, 18, 20 mm

Extended diameter 3.120 mm, for type 3, 5

E = External

I = Internal

TiN, TiCN+TiN, TiALN, (FUTURA NANO), (FUTURA/TOP)

TiALN + WC/C (HARDLUBE), No coating

Std = 30, Mod. = 15 (CYL, no coolant,

l4 max = 2 x Dc1)

Std, Large

Std, Small

Yes (state radius or chamfer) or No

rmm = 0.22

2045 bf mm, (bf = 0.54)


29/90

E 29

Drilling

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C

D

E

F

G

H

Drill specificationsCoroDrill Delta-C

Cylindrical shank Drill diameter: 3.00-20.00 mmMax hole depth: 2-3 x Dc

Coating: TiN/ TiAIN multilayer

Hole tolerance: IT8-9

Surface finish: Ra 1-2 m

Cutting fluid: Emulsion or cutting oil

Drill standard: DIN 6537

Tolerances: dmm = h6

Dc = m7:

Dc 3 +0.012/+0.002

Dc 3 6 +0.016/+0.004

Dc 610 +0.021/+0.006

2 3 Dc

R 840

r70

l4= recommended drilling depth

Internal coolant supply

External coolant supply

Drill diameter: 3.00-20.00 mm

Max hole depth: 4-5 x Dc


Hole tolerance: IT8-9-10





Dc = m7:

Dc 3 +0.012/+0.002

Dc 3 6 +0.016/+0.004

Dc 610 +0.021/+0.006l4= recommended drilling depth



Cylindrical shank

4 5 Dc

R 840

r70









Dc = m7:

Dc 36 +0.016/+0.004

Dc 610 +0.021/+0.006


Internal coolant supplyCylindrical shank

6 7 Dc

R 840

r70









Dc = m7:

Dc 3 +0.012/+0.002

Dc 3 6 +0.016/+0.004

Dc 610 +0.021/+0.006




Whistle Notch shank

2 3 Dc R 840

r70


30/90

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Drill specificationsCoroDrill Delta-C









Dc = m7:

Dc 3 6 +0.016/+0.004

Dc 610 +0.021/+0.006



r70

Whistle Notch shank

4 5 DcR 840

Chamfer drill for tap-size holes

Cylindrical shank

Drill diameter: 3.3514.50 mm

Max hole depth: 23 x DcCoating: TiN/ TiAIN multilayer

Hole tolerance: IT89

Surface finish: Ra 12 m




Dc = m8:

Dc 36 +0.022/+0.004

Dc 610 +0.028/+0.006

Dc 1018 +0.034/+0.007

2 3 Dc

R 841External coolant supply

r70




Coating: TiAIN extra surface finish






Dc = m7:

Dc 36 +0.016/+0.004

Dc 610 +0.021/+0.006


Internal coolant supplyAluminium

2 - 3 Dc

R 850

100



Coating: TiAIN extra surface finish






Dc = m7:

Dc 36 +0.016/+0.004

Dc 610 +0.021/+0.006


Internal coolant supplyAluminium

6 - 7 Dc R 850

100


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32/90

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Dc1

l4

l4a

l21

l2Dc2

ch

pa2

pa3

l4b

dmmD21

1 = Standard type with special diameter and length, Dc1

= 3.020.0 mm

2 = Chamfer drill with extended shank, Dc1

= 3.016.0 mm

3 = Standard type with extended shank, Dc1

= 3.020.0 mm

4 = Step drill, Dc1

= 3.016.0 mm

5 = Chamfer drill with 2 steps and extended shank, Dc1

= 3.016.0 mm

CYL WN

CYL WN

CYL WN

CYL WN

WN

CoroDrill Delta-C R850 Al with cylindrical and Whistle Notch shanks

Shank type

Coolant supply

Options

CYL

External

Internal

Cylindrical CYL

Whistle Notch WN

Drill type

Carbide grade

Tolerance

Tolerance

Mountingtype

Coolant supply

Coating type,

(modified)

Back taper

Diameter 3.020.0 mm

1. 3 Dc1 = 3.020.0 mm/2. 4. 5Dc1 = 3.016.0 mm

H10F and FUTURA TOP recommended

Tolerance on Dc1 = h7/js7/m7 for drill type 1, 2, 3, and

h8/js8/m8 for drill type 4, 5

Drill depth mm Type 13.0-118.5, type 23.0-80. type33.0-118.5



Reach length 9.7155 mm

Overall length 49.7205 mm



Chamfer width 0.52 mm, for drill type 2, 5

Tolerance on Dc2 = h7/js7/m7, for drill type 4, 5

Chamfer angle = 60150, for type 2

Step angle = 60180, for type 4, 5

Step angle = 60150, for type 5

Step length = 5.2120 mm, for type 4

Step length = 8108 mm, for type 5

Cylindrical shank CYL,Whistle Notch shank WN

Mounting size 6, 8, 10, 12, 14, 16, 18, 20 mm

Extended diameter 3.120 mm, for type 3, 5

E = External

I = Internal

TiN, TiCN+TiN, TiALN, (FUTURA NANO),

(FUTURA TOP) recommended, TiALN + WC/C

(HARDLUBE), No coating

Std, Large


33/90

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Hard Cut drill solid carbide drill

Dcmm l2 l3 dmm

2 HC2 30 10 2 M3 4-40 UNC, 6-40 UNF, 6 BA-4 BA3 HC3 40 15 3 M4, M5 8-32 UNC, 10-32 UNF, 3 BA-2 BA4 HC4 45 20 4 M6 1/4-5/16 UNC, 1/4-5/16 UNF, 1 BA-0 BA5 HC5 50 25 5 M8, M10 5/16-3/8 UNC, 5/16-3/8 UNF

6 HC6 60 30 6 M10, M12 3/8-1/2 UNC, 3/8-1/2 UNF

Drilldiameter

Ordering code Dimensions, mm To remove taps

Hard-Cut drills are supplied as follows:

a) In 5 piece sets comprising a drill of each size.

Ordering example for 2 sets: 2 sets HC 23456

b) Drills can also be ordered individually with a minimum quantity

of 3 pieces of each size.

Ordering example for 10 pieces of HC2 drills: 10 pieces HC2

Application

Drills are primarily designed for removal of broken taps, hardened

bolts etc.

Can also be used for drilling in other difficult materials e.g. chilled

cast irons, stellite and glass.

Use machines with a stable spindle.

FMS (flexible machining system), M/C:s, NC and NC-lathes, CNC,

automatics, centre and turret lathes and milling machines.

Geometry

The extra negative geometry produces a high working tempera-

ture anneales the tap.

Regrindable geometry.

No cutting fluid is required drill dry.

Operating procedure when drilling

1. Securely clamp the workpiece

on the machine table in a vice orsimilar rigid work-holding fixture.

Centre the drill on the broken tap.

3. Select the correct size of Hard-Cut

drill according to the list in the

table above. The recommended

spindle speeds are 1500-3500

rpm.Drill with a consistent, steady,

manual feed. Stop frequently to

clear chips from the hole.

2. Centre drill in the unevensurface

of the fractured tap, with a larger,more rigid drill than the one

which will eventually be used for

drilling out the tap.

4. Once the tap has been drilled out

it is a relatively simple matter to

remove the remaining parts of

the tap using a scriber or similar

pointed tool.

5 Dc

For removal of broken taps or drilling difficult materials

Field of

application

For removal of

broken taps


34/90

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Brazed cemented carbide twist-drill

R411.5: drill for precision holes (9.5

30.4 mm diameters)

Hole depths: 3.5 5 times the drill

diameter as standard

Workpiece materials: all kinds

Hole tolerance achievable: IT9

Surface finish achievable: Ra 1 micron

The Coromant Delta (brazed) drill provides

a combination of high productivity and

high quality holes for a wide application

area. Sophisticated drill-centre geometrywith strong cutting edges gives long-last-

ing, reliable performance and stable pre-

cision throughout operations. The rake

angle changes to positive to make centre-

point cutting action more efficient and to

reduce cutting forces conventionally asso-

ciated with twist-drills. Also chip forma-

tion is more advantageous with less ten-

dency for built up edge formation.

Copes easily with drill depths of five

times the drill diameter and more as Tai-

lor Made versions on weak machines,

components and fixtures without major

feed reductions.

Good, basic choice for making accurate

holes in machining centres and specialpurpose machines where the high capac-

ity of the drill can be fully utilized.

Short, extra rigid version available for

drilling depths of up to 3.5 times the drill

diameter. Both versions available with

choice of shank versions.

Careful evaluation of the operation and

quality demands should be made for

choice between the brazed carbide twist-

drill and modern indexable insert drill.

Coromant Delta drill makes precision holes with high productivity and relatively small cutting forces.

Coromant Delta


35/90

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Set up recommendationsWhen using a stationary drill, the total run out between the

centre line of the drill and the workpiece must not exceed 0.02

mm to obtain the tolerance quoted.

Coromant Delta drill

Drilling with holder and housing for cuttingfluid supplyWhen using a holder with a housing for cutting fluid supply a ro-

tating stop to prevent the housing from rotating must be used.

If the bearing seizes, the housing will rotate and consequently

the supply tubing will be pulled round with the housing which

could cause a serious accident.

If the holder has not been used for a long time check that theholder rotates in the housing before the machine spindle is

started.

Rotating stop

Limitations

Drilling against non flat surfaces or drilling workpieces with cross holes is possible

if the feed is reduced to 1/3 1/4 of recommended values.

Max 0.02 mm


36/90

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Cutting fluid volume compensator

When using a drill holder with housing for cutting fluid supply

together with a Coromant Delta drill, a coolant volume compen-

sator should be used.

Only for Coromant Delta drills with Coromant

Whistle Notch shanks.

Chipping of the cutting edge should not

exceed maximum wear recommenda-

tions in order to allow for regrinding and

to obtain maximum tool life.

Recommended maximum wear

1 2 3 1 2 39.50 - 14.00 0.25 0.25 0.25 0.30 0.30 0.30

14.01 - 17.00 0.25 0.25 0.30 0.30 0.30 0.30

17.01 - 20.00 0.30 0.30 0.30 0.35 0.35 0.35

20.01 - 24.00 0.30 0.30 0.40 0.35 0.35 0.35

24.01 - 30.40 0.35 0.35 0.45 0.40 0.40 0.40

Drill diameter

Dcmm

Flank wear

VBmm

Crater wear

KBmm

Zone Zone

Coromant DeltaWear definition

Flank

Drill centreZone

Circular

landFace

Negative

chamfer

VB

KB

12

3

Dcmm

Drill diameter

9.50-14.00 5691 020-01

14.01-17.00 5691 020-0217.01-30.40 5691 020-03

Ordering code


37/90

E 37

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Tailor Made options

Coatings

Balinit FUTURA

Wear resistant coating for steel

and cast iron

Balinit HARDLUBE

Low friction coating for long

chipping materials

H10F

Fine grain carbide. In combination

with Hardlube coating optimized for

stainless steel.

Grades

01

10

20

30

40

P20

P

Steel

Good

Difficult

Averageconditions

K20

K20

M

Stainlesssteel

K

Castiron

N

Aluminium/

Non

-ferrous

H

Hardenedma

terials

K20 K20

Wear resistance

Toughness

Grades for Coromant Delta


38/90

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Cutting data Coromant Delta drill R411.5

ISO

P

M

K

H

1)If chip control is difficult to achieve with the recommended cutting data, reduce the feed to 0.08 - 0.10 mm/rev.

CMC

No.

Material Cutting

speedDrill diameter, mm

Feed fnmm/rvc m/min

Unalloyed steel

Low alloy steel

Non-hardened 0.05-0.10% CNon-hardened 0.10-0.25% C

Non-hardened 0.25-0.55% C

Non-hardened 0.55-0.80% C

High carbon & carbon tool steel

01.001.1

01.2

01.3

01.4

02.1

02.2

03.1103.22

06.1

06.2

05.11

05.21

07.1

07.2

08.1

08.2

09.1

09.2

04.1

30.12

30.21

33.1

33.2

High alloy steel

Extra hard steel

Steel castings Unalloyed

Low alloyed (alloying elements < 5%)

Stainless steel Ferritic, Martensitic 13-25% Cr

Stainless steel Austenitic Ni > 8%, 18-25% Cr

Malleable cast

iron

Ferritic (short chipping)

Pearlitic (long chipping)

Grey cast iron Low tensile strength

High tensile strength

Nodular cast iron Ferritic

Pearlitic

Aluminium alloys

Copper and

copper alloys

Free cutting alloys (Pb 1%)

Brass and leaded bronzes (Pb 1%)

Wrought solution treated and aged

Cast

AnnealedHardened steel

Hardened and tempered

Non-hardened

Hardened

80-170 90-200

125-225

150-225

180-225

150-260

220-400

150-250250-400

90-225

150-250

150-270

150-270

110-145

150-270

150-220

200-330

125-230

200-300

75-150

40-100

50-160

Grade

HB

75-100 0.14-0.22 0.15-0.25 0.18-0.31

70-90 0.15-0.23 0.18-0.26 0.20-0.30

55-90 0.14-0.22 0.18-0.26 0.20-0.28

35-65 0.14-0.22 0.15-0.25 0.18-0.26

40-70 0.15-0.20 0.18-0.25 0.20-0.2740-60 0.15-0.20 0.17-0.20 0.18-0.24

70-90 0.17-0.23 0.19-0.25 0.20-0.26

50-75 0.15-0.21 0.17-0.23 0.19-0.25

25-55 0.14-0.21 0.17-0.24 0.18-0.27

25-55 0.14-0.201) 0.16-0.231) 0.19-0.251)

75-120 0.15-0.26 0.18-0.30 0.21-0.39

75-110 0.15-0.25 0.16-0.29 0.18-0.35

85-115 0.19-0.31 0.23-0.39 0.26-0.46

55-100 0.19-0.30 0.24-0.36 0.28-0.44

65-105 0.16-0.26 0.20-0.35 0.23-0.41

55-95 0.15-0.25 0.18-0.33 0.21-0.39

25-40 0.10-0.15 0.12-0.17 0.15-0.20

15-30

95-150 0.21-0.33 0.18-0.41 0.18-0.41

45-150 0.16-0.29 0.20-0.35 0.25-0.44

P20

P20

P20

P20

P20

K20

K20

K20

K20

K20

K20

K20

9.50-14

14.01-17

17.01-30.40

HRC43-47

47-60

N


39/90

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Graphs Coromant Delta drill R411.5

The graphs show nominal values which should not be regarded

as strict recommendations. The values may need adjusting de-

pending on the machining conditions e.g., the type of material.

Note that only net power ratings are given. Allowance must be

made for the efficiency of the machine and the cutting edge

wear.

Feed force Net power

Cutting fluid flow

Min

[l/min]

Drill diameter

0 10 15 20 25 30 Dc[mm]

q 16

14

12

10

8

6

4

2

0

Ff= 0.5 Dc fn kcfz sinr [N] 2

(Only for solid drilling)Ff

[kN]

8

6

4

2

0

Drill diameter

0 10 15 20 25 30 Dc [mm]

Pc=Dc fn kcfz vc

[kW] 240 x 103

(Only for solid drilling)kW8

6

4

2

0

Drill diameter

0 10 15 20 25 30 Dc [mm]


40/90

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Cylindrical with flatCYLPF CylindricalCYL Coromant Whistle NotchCWN

1= Lengths and diameters different to standard, Dc= 9.50-30.40 mm

2= Drill with chamfering insert, Dc= 12.25-30.40 mm

3= Drill with pilot, Dc= 9.50-30.40 mm

4= Drill with pilot and with chamfering insert, Dc= 12.25-30.40 mm

P M K H N

Coromant Delta drill R411.5

Dc

9.50-30.40 16, 20

, 25, 32 16, 20, 25, 32 16, 20, 25

Drill diameter Mounting type

Cylindricalwith flat

Mounting size, dmm

Cylindrical CoromantWhistle Notch

Options

Dc

ch

l3s

l4

dmm

D21

l21

D1

l1s

l2

l6

Drill type

Mounting

type

Carbide

grade

Coating

Diameter9.50-30.40 mm

1. 3Dc= 9.50-30.40 mm1=standard

2. 4Dc=12.25-30.40 mm

Chamfer width0.5-1.5 mm,

only valid for type 2 and 4

Drill lengthDrill type 1 and 217-158 mm

Drill type 3 and 417-140 mm

Drill depthType 1 9.9-134.8 mm

Type 216.4-134.8 mm

Type 3 9.9-116.8 mm

Type 416.4-116.8 mm

Cylindrical shank with flatCYLPF,

Cylindrical shankCYL,

Coromant Whistle NotchCWN

Mounting sizesee above

Pilot diameter10-31 mm, only valid for

type 3 and 4

Pilot length18.6-158 mm, only valid for

type 3 and 4

Flange diameter15-32 mm

Programming length44-175 mm,

depending on l3s, l4, l21

Overall length92-236 mm, depending on l3s, l4, l21

Flute length17-172 mm,

depending on Dc and dmm

P20 for general steel applications

K20 for stainless steel, cast iron and aluminium

H10F for stainless steel, titanium and aluminium

PVD coating: TiN, TiCN, TiALN (FUTURA),

TiALN + WC/C (HARDLUBE)


41/90

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H10F

L142.01-05 06 00 3113 030-304

Ordering example: 5 pieces L142.01-05 06 00 H10F

10

3.8 0-0.2

112.5 0.1

r=1

5 0-0.02

4 0.04

90 1545 20

0.4 0.1 45

6 0.2

4 0-0.2

Drills with the chamfering insert mounted are available as

Tailor Made. See next page for detailed information.

Chamfering insert for Coromant Delta drills

Ordering code

Insert

Spare parts

Tension pin (delivered with the insert).

Coromant

grade

2H8

2.5 0.03

0.2 0.1 45

4 0+0.2

5H8

l21

l4

l21= l4+ 2.1 - ch

l21= l4+ 2.1 - ch

ch (45)

2.1

l4

Dc

Building in dimensions

P M K H N

Max. chamfer size 1.5 x 45

Drill dia. > 12.25 mm

l21

l4chmax = 1.5 45 0.3

= Position of chamfering insert

= Drill depth


42/90

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Drill specificationsCoromant Delta

3.5 Dc

R 411.5

r70

Cylindrical shank with flat according to ISO 9766


Hole depth: 3.5 Dc



Cutting fluid: Emulsion or

Neat oil

Tolerances: Dc = js7

dmm = h6

l4= Recommended drilling depth

r70

Cylindrical shank with flat according to ISO 9766


Hole depth: 5 Dc




Neat oil


dmm = h6


5 Dc

R 411.5

Whistle Notch shank


Hole depth: 3.5 Dc




Neat oil


dmm = h6

r70

l1s

= Programming length


3.5 Dc

R 411.5

r70

Whistle Notch shank


Hole depth: 5 Dc




Neat oil


dm = h6

l1s= Programming lengthl4= Recommended drilling depth

5 Dc

R 411.5


43/90

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Indexable insert drills

CoroDrill 880 drill, Coromant U drills and T-Max U drills and trepanning tool

CoroDrill 880: first choice for short

hole drilling (14 29 mm diameters)

R416.2: tool for short hole drilling

( 12.7 58 mm diameters)

R416.21: step and chamfer combina-

tion drill (17.5 41 mm diameters)

L416.1: left-hand drill (17.5 58 mm

diameters)

R416.01: stack drill (27 59 mm

diameters)

R416.9: large-diameter drill (60 80

mm diameters)

R416.7: trepanning tools (60 110

mm diameters)

Hole depths: up to 4 times the drill dia-

meter (5 for Tailor made drills)

Workpiece materials: all kinds

Hole tolerances: generally 0.1/+ 0.3

mm but CoroDrill 880 provides a

0/+ 0.25 mm tolerance, when used infinishing operation tolerances within

+/- 0.05 mm are kept and Wiper

technology gives good surface finsih.

With the right choice of drill- type, size

and shank, along with tool holder - most

hole making operations can today be

performed in a very efficient way. A wide

range of machine tools are used, includ-

ing special-purpose machines, although

CNC lathes, turning centres and machin-

ing centres dominate with a growing

number of multi-task machines.

Todays range of drills covers a wide vari-

ety of applications and when the right

drill has been selected, the tool can be

optimized to suit the operation. Indexa-

ble insert drills generally offer clear ad-

vantages in most respects and for holes

falling within their capability, these

should be considered as first choice forstationary and rotating set-ups.

With their increased capability to pro-

duce closer tolerances and better sur-

face finish, the indexable insert drill is a

very versatile tool as regards materials,

machinery and operation.

The indexable insert drill combines the

toughness of a steel drill-shank with the

wear resistance of cemented carbide in-

serts, without the need for re-grinding.

The life of the drill is long and can be ap-

plied to suit different machining demands.

Reliability and accuracy is higher than

ever, coupled with the ability to produce

good machining economics.

The following few application hints will

ensure smooth performance and opti-

mum results.

CoroDrill 880 T-Max U stack drill R416.01 T-Max U trepanning tool R416.7

Coromant U drill R416.2 T-Max U large-diameter drill R416.9

Operational possibilities with indexable insert drills.


44/90

E 44

Drilling

A

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C

D

E

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H

Application hints

Correct alignment of the drill is vital.

There is about as many stationary drills

as rotating since they are often used in

CNC lathe turrets where the workpiece

revolves. In these cases, it is important

to ensure that the centre axis of the drillis sufficiently aligned to the rotary axis of

the workpiece. Faulty centering run-out

- is the most common cause of poor tool

performance and bad results.

The drill should also be set up so that

the face of the peripheral insert is par-

allel to the machine axis of transverse

movement.

Misalignment also has the effect of ra-

dial off-setting, which produces either anover-sized or under-sized hole.

Rotating drill alignment can be some-

what more demanding but not difficult

if a few guidelines are followed. If there

are problems with oversize or undersize

holes or if the centre insert tends to chip

or break, the drill should be positioned

in different ways until it achieves better

results. For instance, if the drill cuts over-

size in one position, it should cut under-

size in another.

Turning the drill 180 degrees in its holder

may solve the described problem of hole

such as spindle, chuck, tool holder or

the drill itself, the centre axis of the drill

and axis of rotation may not be suffi-ciently parallel which then gives rise to

inaccurate holes. In order to achieve the

tolerances of the drill capability, it is im-

portant that the centering between the

workpiece and the drill is within certain

limits:

Stationary indexable insert drills can

also generate tapered holes, with the

help of the CNC programme. Also cham-

fering and reliefs can be cut with the drill.

When off-setting the drill, the peripheral

insert should be parallel to the x-axis of

the machine. The peripheral insert is lo-

cated on the same side as and parallel

to the flat for clamping the ISO-shank.

The position of the drill in the turret will

then determine the off-set which will in-

crease the hole diameter.

Correct drill alignment is critical.

size. In fact, various types of reposition-

ing often lead to dimensional and align-

ment deviations being eliminated.

When the workpiece and drill are out of

true, due to inaccuracy in the machine,


45/90

E 45

Drilling

A

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C

D

E

F

G

H

Preparing a hole for threading can be

done in one pass along with chamfering

(A).

Larger holes than the diameter of the

drill (B).

Drilling and finishingcan be done in one

operation where boring is performed dur-

ing withdrawal of the drill (C).Possible radial adjustment depends

upon the diameter of the drill.

Hole tolerances are possible to within

+/-0.05 mm.

By presetting stationary drills, manufactur-

ing tolerances of drill and insert

e - drilling

Documents