Chisels and punches
Chisels
Cold flat chisels are most often used to remove rusty nuts or bolts whose heads are rounded or damaged. For this purpose, we choose a cutter with a flat blade made of high-quality steel. The cutting angle is about 70 °. The tip of the chisel is hardened and is stronger than the metals it is cutting. The head of the chisel needs to be softer so it will not chip when it is hit with a hammer.
The cross-cut chisel has a blade at the top along the width of the blade. It is used for cleaning canals or making new ones.
Because the chisel heads are softer than hammers, over time, the top of the head deforms and there is a possibility of separating small fragments that can injure us. Occasionally, damaged parts of the chisel tip should be removed with a grinder.
Cold flat and cross-cut chisels
Prick and center punches
Prick and center punches are used for precise marking on sheet metal or plates.
The prick punch has a thin and very sharp tip so that a light blow of the hammer leaves a clear indentation. They can also be used to scribe intersecting lines between given points.
A center punch is used to mark the center. It makes a bigger indentation that centers a drill bit at the point where a hole is required to be drilled. This marker has a wider tip and can be applied over a dotted recess. The top angle is between 60 ° and 90 °.
Drift and pin punches
Drift and pin punches are used where the hammer head cannot reach without damaging the surrounding parts. The hammer blow is precisely transmitted from the soft upper part of the hammer to the hard tip made of hardened steel.
The drift punch is used to align the screw holes between two surfaces, such as the valve cover and the cylinder head. The top of the conical end is placed in semi-aligned holes and by slightly inserting the cone we align the holes. After aligning the opening, it is easier to insert a screw to connect the two surfaces.
Pin punches are used to drive out pins or rivets. They are available in various diameters and have a long slender shaft.
