Cold chisels cut and shear metal. The cutting edge is ground to an angle that depends on the material — a sharper angle for softer metals, a blunter angle for hard steel, because a fine edge chips under impact. Chisel type follows the cut: flat chisels for shearing, cape chisels for narrow grooves, diamond-point for cleaning corners, round-nose for oil grooves.
Punches mark and locate. Centre punches mark hole locations; prick punches mark a scribed line; pin punches drive out pins and rivets; taper punches align holes; knockout punches cut holes in sheet metal and electrical boxes. Each is sized to the work.
Safety is a real concern with struck tools. Mushroomed heads — where repeated hammering has spread the head — throw fragments. The head should be dressed back to shape or the tool replaced. Eye protection is mandatory, and the correct hammer weight matters: too light and the chisel bounces, too heavy and the edge chips.
