Chisels & Punches

Chisels and Punches for Metalworking and Construction

Chisels and punches are hand-driven cutting and marking tools used in metalworking, masonry, woodworking, and construction. Cold chisels cut soft metal (copper, brass, mild steel) without heat; wood chisels shape and pare wood joints; masonry chisels break concrete, brick, and stone. Center punches mark drilling points to prevent drill bit walking; drift punches drive pins and align holes. These tools combine hardened cutting edges with impact forces that create specific injury hazards managed by proper technique and PPE.

Eye protection is the most critical PPE for chisel and punch work. Cold chisels struck with a hammer generate metal chips and scale at high velocity—chip speeds of 200–300 feet per second have been measured in laboratory testing. Z87.1-rated safety glasses with side shields are the minimum; a full polycarbonate face shield provides superior coverage for overhead chisel work or applications where chip direction is unpredictable. Never work with chisels without eye protection.

Mushroomed Head Hazards

The most specific hazard of cold chisels and drift punches is the "mushroomed head"—when the struck end of a tool is repeatedly hammered, the steel deforms and spreads into a flanged rim of hardened metal. When struck again, this mushroom rim can shatter and fly outward at high velocity. Inspect chisel and punch struck ends before each use and grind any mushrooming back to a chamfered profile before using the tool. Do not use any chisel or punch with a cracked, chipped, or significantly mushroomed struck end—the risk of fragmentation injury is real and preventable.

Use hammer weight matched to chisel size: light chisels require light ball-peen hammers (16–32 oz); heavy cold chisels and masonry chisels require heavier single-jack or drilling hammers (2–4 lb). An undersized hammer requires excessive swing force and poor control; an oversized hammer delivers too much energy per strike, bending chisels and increasing kickback.

Edge Maintenance

A sharp chisel requires less force to cut—less force means better control and reduced injury risk. Sharpen cold chisels on a bench grinder or angle grinder at the appropriate cutting angle (60–70 degrees for cold chisels, 25–35 degrees for wood chisels). Overheating the cutting edge during grinding destroys the hardness treatment—grind in short passes and cool with water. Keep wood chisels sharp with a sharpening stone and honing compound for the finest edge quality.