Rotary saw

A rotary saw or spiral cut saw is a type of mechanically powered saw used for making accurate cuts without the need for a pilot hole in wallboard, plywood, or another thin, solid material.

Another name commonly used to refer to this type of tool is RotoZip, from the Rotozip Tool Corp. a company set up by Bob Kopras, an American drywall installer who pioneered this type of saw. Rotozip was later acquired by Bosch Tool Corp. in 2003.

This type of tool was originally developed for making cut-outs in drywall but it was later discovered that a myriad of other materials could easily be cut using the tool.

The design is similar to a small wood router but usually features only one handle for single handed operation. Bits look similar to a twist drill; some cut on the upward twist, and some cut downwards. The cutting edge on the flutes actually slices (either upwards or downwards) through the material which means that they can cut in any direction.