Mechanical Engineering - Workshop Technology - Discussion

Octagonal has 8 sides in the chisel.

How is it possible please explain?

I think it should be rectangular.

The correct answer is rectangular.

The cross-section of a chisel is typically rectangular, with a flat, broad blade and a straight or slightly curved edge. This shape allows for:

- Efficient removal of material.
- Good control and leverage.
- Effective transmission of force to the cutting edge.

Here's why the other options are incorrect:

- Square: A square cross-section would make the chisel prone to twisting and digging in, rather than smoothly removing material.
- Hexagonal: A hexagonal cross-section is not typical for chisels, and would not provide the same level of control and leverage as a rectangular shape.
- Octagonal: An octagonal cross-section is also not typical for chisels, and would likely make the tool more difficult to handle and control.

Rectangular chisels are commonly used for:

- Removing small amounts of material.
- Parrying and shaping wood or metal.
- Scoring and breaking up material.

=> Note that some specialized chisels, like paring chisels or skew chisels, may have slightly different cross-sectional shapes, but rectangular is the most common and versatile shape.