A Bi-Metal Cobalt Hole Saws are a type of hand tool with a 4/6 variable tooth pitch and 1-1/2" cutting depth designed exactly for cutting through materials such as plastic, steel, and other metals. You will find a collection of hole saws available in our store. Some are meant for very specific tasks, while others are good for a range of projects. They are also referred to as hole cutters or hole drill bits. The hole saw is designed for cutting perfectly round holes in a variety of applications.