The Complete Handbook of Hole Punches

Chapter 1: Understanding Hole Punches

A hole punch is a machine for a single, precise task: removing a carefully shaped piece of material, usually paper, to create a hole. This action is so common that it is easy to overlook the mechanical sophistication involved in doing it well, consistently, and without tearing the workpiece, and even the lowliest office punch is the product of decades of refinement.

At its core, a hole punch works on the principle of direct shear. A sharpened, hard-steel punch (the moving part) is forced through the material and into a mating hole in a die (the stationary part). The material fails along the shearing line between the sharpened edge of the punch and the sharpened edge of the die. The quality of the cut is determined by the clearance between the punch and the die, the geometry of the cutting edges, and the condition of those edges. This is a subtractive process; you are not bending or tearing the paper, you are slicing it in a straight line.

Consider the standard office two-hole punch. When you press the lever, you are applying force to a mechanism that amplifies your muscle power. This mechanism might be a simple linkage, a rack and pinion, or a cam. The force is translated into downward travel of the punch pins. The pins meet the paper, which rests on a platform, and the punch pin enters the die hole. For the tool to do its job, the paper must be