Lesson No.08

Week No.

05

Lesson Name

Chisel

CHISEL Use:- To chip and cut flat surfaces, slots and grooves.

Material:- High carbon steel or Chrome vanadium steel

Types:- A. Cold chisel B. Hot Chisel

HeadBody

Point

Flat Chisel

Use:- They are used to remove metal from large flat surface and chip excess metal weld joints and castings.

Cross cut Chisel

Use:- These are used for cutting keyways, grooves and slots.

Use:- They are used for cutting curved grooves (oil grooves)

Half round nose Chisel

Use:- These are used for squaring materials at the corners.

Diamond point chisel

Use:- These chisels are used for separating metals after chain drilling.

Web Chisel

Point angle

Point angle:- The correct point/ cutting angle of the chisel depends on the material to be chipped. Sharp angles are given for soft material and wide angles for hard material.

The correct point angle and angle of inclination generates the correct rake and clearance angle

Inclination angle

Rake angle

Rake angle:- Rake angle is the angle between the top face of the cutting point and normal to the work surface at the cutting edge.Cleara

nce angle

Clearance angle:- Clearance angle is the angle between the bottom face of the point and tangent to the work surface originating at the cutting edge.

If the clearance angle is too low or zero, the rake angle increases. The cutting edge cannot penetrate into the work. The chisel will slip. If the clearance angle is too great, the cut progressively increases.

1. List the type of chisel2. What are the parts of Chisel?3. Which material is used in Chisel?4. What is the use of Chisel?

QUESTIONS

CONCLUSION

Thus, we learnt about chisel.