What is a hole saw?
A hole saw is a ring-shaped saw blade attachment used in conjunction with a power drill.
The hole saw consists of a cylindrical saw blade mounted on an arbor, which is a spindle-like tool that is used to grip other moving tool components. As with many hole saws, there is often a drill bit attached to the arbor.
Hole saws often have drill bit attached so that, prior to cutting, you can make a starter hole that will keep the saw blade aligned and secure. The starter hole is known as a "pilot hole".
The hole saw attaches to the power drill via the arbor and the drill's chuck (most commonly 3/8 and 1/2 inch drill chucks). It is then rotated at high speeds and used to cut holes in a variety of materials such as wood, metal, plastic and even brickwork.
These circular holes are often created prior to installing drainage pipes and plumbing fittings as well as for many other applications.