Punch (tool)

A punch is a tool used to indent or create a hole through a hard surface. They usually consist of a hard metal rod with a narrow tip at one end and a broad flat "butt" at the other. When used, the narrower end is pointed against a target surface and the broad end is struck with a hammer or mallet, causing the blunt force of the blow to be transmitted through the rod body and focused more sharply onto a small area. Typically, woodworkers use a ball-peen hammer to strike a punch.

Punches are used to drive fasteners such as nails and dowels, making a hole, or forming an indentation or impression of the tip on a work piece. Decorative punches may also be used to create a pattern or even form an image.^{[citation needed]}

Metal pins and similar connectors are driven in or out of holes using a pin punch.

For removal, first use a starter punch to loosen the pin, then use a pin punch to finish.

A center punch is used to mark the center of a point. It is usually used to mark the center of a hole when drilling holes. A drill has the tendency to "wander" if it does not start in a recess. A center punch forms a large enough dimple to "guide" the tip of the drill. The tip of a center punch has an angle between 60 and 90 degrees. When drilling larger holes, where the drill bit is wider than the indentation produced by a center punch, the drilling of a pilot hole is usually needed.

An automatic center punch operates without the need for a hammer.

A prick punch is similar to a center punch but used for marking out. It has a sharper angled tip to produce a narrower and deeper indentation. The indentation can then be enlarged with a center punch for drilling. The tip of a prick punch is 60 degrees (the angle depends on what type of prick punch one is using). It is also known as a dot punch.

A transfer punch is a punch (usually in an index set) of a specific outer diameter that is non-tapered and extends the entire length of the punch (except for the tip). It is used to tightly fit the tolerances of an existing hole and, when struck, precisely transfer the center of that hole to another surface. It can be used, for example, to duplicate the hole patterns in a part, or precisely set locations for threaded holes (created by drilling and tapping) to bolt an object to a surface.