A rotary saw, which can also be called a spiral cut saw and is often sold as a RotoZip®, is a powered mechanical saw that is designed primarily to cut precisely through drywall and other similar materials, such as wood, soft tile, aluminum siding, plastics and more. The tool works similarly to a drill, except that rather than drilling straight holes into a surface, the drill bit is used to cut out lines and patterns like a saw. The rotary saw was originally invented in 1970 by Bob Kopras, who called it the RotoZip®, promoted the tool and started the RotoZip® Tool Corporation, which was eventually bought by the Bosch Tool Corporation in 2003.
If a traditional saw was being used to cut a shape out of a wall, a pilot hole would need to be created first since a saw cannot simple cut straight into a flat surface. A rotary saw eliminates the need for a pilot hole because it uses a spinning bit to do the cutting, which can be drilled directly into the first point where the desired cutting is to begin. Once cutting, the drill can be moved in any direction, so if the pattern that is being sawed out is drawn on the surface being worked on, the operator only has to cut along the predetermined path.
Rotary saws are designed for one-handed use, with a single handle to grip the tool. Rotary saw bits are detachable, and there are many different styles that can be attached depending on the type of work that it is being used for. Some twist towards the saw to cut, while others twist away from the saw, and many types of bits are designed specifically for a certain type of material. They also vary in diameter, so the width of the line being cut can vary as well. In addition to rotary saw bits, different cutting wheels can be attached to a rotary saw, which can be used to cut through more dense materials such as metal, brick, stone and more, and can also be designed for sanding.
There is a guide at the drilling end of the rotary that lays flat against the surface that is being sawed through. This can also be interchanged with specialized guides; for example, a straight edge guide can be attached when it is crucial that the saw cuts a perfectly straight line. Other attachments are made for the RotoZip®, for example some that keep the surface clear of dust, others that are designed for grout removal, and more. Using a rotary saw can be a particularly dusty and messy when cutting through drywall and other materials. This also makes safety goggles, a dust mask, and other protection essential when using this handy tool.