The Complete Handbook of Hole Saws

Chapter 1: Understanding Hole Saws

A hole saw is a circular cutting tool with a serrated edge designed to cut a cylindrical plug out of a material, leaving a clean hole. Unlike a twist drill bit, which grinds away all material to create a hole, a hole saw only cuts the perimeter of the circle. The material in the center, the core, is left intact and is often ejected as a single plug. This fundamental difference makes the hole saw the most efficient tool in a professional's arsenal for creating holes larger than about 3/8 of an inch in diameter. Attempting to drill a 2-inch hole with a standard twist bit is a slow, expensive exercise in inefficient material removal; a hole saw accomplishes the same task in seconds, using far less energy and producing a vastly cleaner result.

To understand why a hole saw works so well, you have to look at its anatomy. A standard hole saw is essentially a short metal cylinder with teeth cut into one open end. The other end is capped, and has a threaded hole in its center. This cap is where the arbor attaches. The arbor is the driving mechanism that connects the saw to the drill chuck. The arbor has a threaded stud that screws into the cap of the saw, and on the other end, a hex-shaped shaft that can be tightened in a drill chuck. Most arbors also have a built-in pilot drill bit that protrudes through the center