BasicDesign Guidefor

This book is a guide to designing parts formanufacturing with the GRIPflow process.We suggest that you have our firm reveiwyour requirements and share our manufac-turing expertise as it relates to your spe-cific needs.

EBWAY CORPORATION 6750 N.W. 21 Avenue Fort Lauderdale, Florida 33309 954/971-4911

TABLE OF CONTENTSDESIGN

GUIDE

TABLE OF CONTENTS

What is GRIPflow?.............................................................................Page 1How is GRIPflow different? ..................................................................Page 2Design your part to reduce cost ..........................................................Page 3Die-Roll.............................................................................................Page 4Edge Taper .......................................................................................Page 5Radii on corners................................................................................Page 6Tears ...............................................................................................Page 7Close Web Sections, Small Hole Diameters and Slots ............................Page 8Hole Tolerances.................................................................................Page 9Tooth Forms and Gear Sections...........................................................Page 10Projections .......................................................................................Page 11Countersinks and Chamfers ................................................................Page 12Offsets .............................................................................................Page 13Flatness ...........................................................................................Page 14Tonnage ...........................................................................................Page 15Material Selection..............................................................................Page 16

WHAT IS GRIPFLOW?DESIGN

GUIDE

Page 1

GRIPflow is a patented metal stampingprocess that produces highly accurateparts with smooth square edges.

The process requires a single actionGRIPflow press and precision-built dieswith tight tolerances between punchand die.

In the stamping operation, before thematerial is actually blanked, it is firmlyclamped in the area of the stamping.The scrap material is allowed to flowlaterally. Hence, the name GRIPflow.

GRIPflow can: Eliminate secondary machine

operations. Pierce holes smaller in diameter

than the stock thickness. Coin countersinks the entire

thickness of the stock material. Stamp gear teeth. Hold close tolerances. Make the smooth-edge only

where it is required. Improve your parts flatness.

The following is requiredto manufacture GRIPflowParts

GRIPflow Press GRIPflow Tool Malleable Material

HOW IS GRIPFLOW DIFFERENT?DESIGN

GUIDE

Page 2

Conventional stamping bends the actu-al blank at the start of the blankingoperation. Due to this bending, there isno smooth, fully continuous edge.Approximately 30% of the thickness issheared while the remaining 70%tears. Rough edges and poor toler-ances are the evident results. Typicaledge-surface finish is 125-150 RMS.

GRIPflow combines cutting and metalflow to produce smooth (no tear), ver-tical, accurate sides through-out theentire part thickness. GRIPflow rou-tinely holds accuracies of .001 andcertain dimensions are held to .0005.Almost no difference can be measuredbetween the first and the millionth partout of the tool. This is achieved on asingle action punch press. Typical sur-face finish is 16-32 RMS.

Fineblanking requires a special triple-action press and a V ring in the die torestrict the material from moving awayfrom the shear zone during the blank-ing operation (opposite of GRIPflow).This V-Ring requires extra stock mate-rial and press tonnage (maximum of40% of total blanking tonnage).

Accuracies in most cases are similarto, or equal to, those of GRIPflow.

TAPER

PUNCHPUNCH

SMOOTHEDGE

BURRDIE-BREAKDIE-ROLL

CONVENTIONAL

PUNCH

SHEDDER

FLOW

STRIPPER

DIE

GRIPFLOW

DIE-ROLL

BURRSMOOTH EDGE

GRIPFLOW

BURR

DIE-ROLLSMOOTH EDGE

DIE

V-RING

V-RINGPRESSURE

COUNTERPRESSURE

PUNCH

FINEBLANKED

DESIGN YOUR PART TO REDUCE COSTDESIGN

GUIDE

Page 3

BASIC GUIDELINES

1.) Draw the part as it will look. Thestamped part will have die-roll onone side and a burr on the oppo-site side (this burr is removed byvibratory deburring). Identify thedie-roll or the burr side on yourpart.

2.) Identify the area(s) on the part thatrequire a smooth edge with a bro-ken line.

3.) Specify the amount of smooth-edgerequired (i.e. 50%, 75%, 90%,etc.).

.375 .001 90%

EDGE

DIE-ROLLSIDE

BURRSIDE

B70%

A

The less smooth-edge on a part, thesmaller the burr and the lower theprice because of:

less deburring less tool maintenance a faster production rate

Why pay for a total smooth-edgestamping when only specific portionsof the stamping require a smooth-edge?

GRIPflow can give you the smooth-edgeonly where it is required.

DIE-ROLLDESIGN

GUIDE

Page 4

Die-Roll is produced on all stampedparts. The degree of die-roll is influ-ence by:

1.) Material2.) Material Thickness3.) Part Shape

The harder the material The less the die-roll

The more acute the corner The greater the die-roll

The smaller the corner radius The greater the die-roll

The thicker the material The greater the die-roll

Y = 2XY

DIE-ROLL SIDE

X

BURR SIDE

DIE-ROLL = XS

S = 100%Material Thickness

GRIPflow DIE-ROLL IN PERCENT OFTHE MATERIAL THICKNESS

(BASED ON MATERIAL OF57,000 P.S.I. TENSILE STRENGTH)

1-10%

15-25%

6-12%

0-2%

4-10%

0%

20-30%

DISHING OCCURS WHEN

W IS LESS THAN S

W

90 CORNERS

CURVEDCONTOURSON LARGEHOLES

CORNERSON INSIDECONTOURS

ACUTE CORNERSLESS THAN 90

HOLESSMALLERTHANMATERIALTHICKNESS

STRAIGHTCONTOURS

EDGE TAPERDESIGN

GUIDE

Page 5

The GRIPflow Edge Taper isinfluenced by:

1.) Material The thicker the material

The greater the edge taper The higher the carbon

The greater the edge taper The greater the alloy content

The greater the edge taper

2.) Shape of Part Outside contours have a larger

degree of edge taper thaninternal contours

LESS THAN1 DEGREE

SMOOTHEDGE

ONLY 30%SMOOTHEDGE

DIE-BREAK

MAXIMUMDIE-BREAK OF30 DEGREES

GRIPflow EDGE

CONVENTIONAL EDGE

RADII ON CORNERSDESIGN

GUIDE

Page 6

The extrusion type characteristics ofGRIPflow require sharp corners tohave a blending radius. This radiusallows for a smooth, uninterruptedflow of the metal during blanking.Sharp corners should be avoided wher-ever possible. If a sharp corner isabsolutely necessary, it may be accom-plished by utilizing a progressive tool.

The larger the radius---The less corner tear

The larger the radius---The less die wear

The larger the radius---The less die-roll

The harder the material---The larger the radius

OBTUSEEXTERNAL CORNER(OUTSIDE CONTOUR)

OBTUSEINTERNAL CORNER(OUTSIDE CONTOUR)

ACUTEINTERNAL CORNER(INSIDE CONTOUR)

ACUTEEXTERNAL CORNER(OUTSIDE CONTOUR)

90 INTERNALCORNER(INSIDE CONTOUR)

OBTUSEEXTERNAL CORNER(INSIDE CONTOUR)

OBTUSEINTERNAL CORNER(OUTSIDE CONTOUR)

DESIGN GUIDELINESTYPE OF CORNER INSIDE

CONTOUROUTSIDECONTOUR

% OF MATERIALTHICKNESS

YES

YES

YES

YES

YES

YES

7 - 12%

10 - 15%

11 - 15%

15 - 20%

4 - 7%

5 - 10%

90 Corner

AcuteCorner

ObtuseCorner

TEARSDESIGN

GUIDE

Page 7

Edge Tears Result From:

Material being too hard having a poor grain structure

Tooling having a worn or chippedpunch

Corner Tears Occur Only On ExternalCorners. Causes May Be:

Design corner radii too small

Material being to hard having a poor grain structure

Tooling worn or chipped punch

EDGE TEAR

CORNER TEAR

CLOSE WEB SECTIONS, SMALL HOLEDIAMETERS AND SLOTS

DESIGNGUIDE

Page 8

Design Guidelines based on 57,000p.s.i. Tensile Strength (i.e. AISI 1010hot rolled steel) Minimum Protrusion Width

If 0 < S then V=1/2 SIf 0 S then U=2/3 S

Minimum Hole DiameterR=1/2 S

Minimum Hole WebX=1/2 S

Minimum Slot WidthP=1/2 S

Minimum Slot WebT=1/2 S

Minimum Notch WidthW=1/2 S

O - Protrusion LengthP - Slot WidthR - Hole DiameterS - Material ThicknessT - Web (Slots)U - Protrusion Width (If OS)V - Protrusion Width (If O

HOLE TOLERANCESDESIGN

GUIDE

Page 9

Dimensional accuracy of a GRIPflowpart is primarily dependent on the qual-ity of the tool.

Tolerance range is influenced by: Material Thickness Tensile Strength of Material Grain Structure of Material Configuration of Part

Closer tolerances can be held, ifrequired by designing a more involvedand complex tool.

Tolerances on internal contours areeasier to maintain than outside con-tour tolerances.

TOLERANCESBASED ON 57,000 PSI TENSILE

STRENGTH MATERIAL (i.e. AISI 1010)

MATERIAL THICKNESS

Hole Diameter

.118 - .236

.237 - .393

.394 - .708

.709 - 1.181

1.182 - 1.968

1.969 - 3.149

3.150 - 4.724

4.725 - 7.086

Up to .157