Hand Tools - Struck Tools

Struck tools or hammered tools are made in various shapes and sizes and for many uses and include cold chisels, punches, drift pins, nail sets, rock and star drills, and wedges. Use the correct tool for the job.

DO

• Wear safety glasses or goggles or a face shield (with safety glasses or goggles).
• Use a screen or shield to protect fellow workers from flying chips.
• Use the tools only if they are in good condition (i.e., cutting edges are sharp, struck head is not mushroomed or chipped).
• Hold the chisel for shearing and chipping, at an angle which permits the bevel of the cutting edge to lie flat against the shearing plane.
• Provide hand protection.

• Hand protection can be provided by a sponge rubber shield forced onto the shaft of a chisel or select struck tools that come with hand protectors designed for the tool.
• Use holders for punches and chisels.

• Redress the point or cutting edge to its original shape. Grind to a slightly convex cutting edge. The point angle of the chisel should be 70° for hard metals and 60° for soft.

• Discard tools that are bent, cracked, or chipped.
• Redress striking tools with burred or mushroomed heads.
• Use punches and pins strong enough for the work.
• Hold the punches and pins firmly in position before hitting them on the rounded surfaces.

• Do not use struck tools if the struck end is chipped or mushroomed.
• Do not use struck tools if the cutting edge is dull or chipped or if the point of a punch is slanted or damaged.
• Do not apply too much pressure to the head when grinding a chisel. The heat generated can remove the temper. Immerse the chisel in cold water periodically when grinding.
• Do not use cold chisels for cutting or splitting stone or concrete.
• Do not use a drift pin punch (also called an aligning punch) as a pin punch intended for driving, removing, or loosening pins, keys, and rivets.
• Do not bend or break pins.
• Do not jam tapered parts of punches into openings.
• Do not allow bull point chisels to be hand-held by one employee and struck by another. Use tongs or a chisel holder to guide the chisel so that the holder's hand will not be injured.

Refer to OSH Answers General Hand Tool Operation for more tips.