A cutoff wheel is a disc-shaped abrasive attached to a powered motor that spins the disc at a high rate of speed. This speed, along with the disc shape and the material the cutoff wheel is made out of, determines the type of material the wheel is able to effectively cut into. In most construction applications, the cutoff wheel is used to cut the ends off of metal tubing or concrete reinforcements that protrude from the wall or slab. For larger industrial applications, the cutoff wheel may have its own dedicated power supply, but in many smaller applications the cutoff wheels with smaller diameters can be put on a hand grinder unit or even a powered drill.
The disc of a cutoff wheel is usually available in different material grades, and each material is used for a different application. For instance, when a cutoff wheel is going to be used mainly for cutting ends off of metal tubing or “rebar,” the cutoff wheel itself will be made of a hardened material. It will also usually be coated with an abrasive that helps it cut through the material without “chewing” the material being cut, leaving as smooth an edge on the tubing or rebar as possible. There are also softer abrasive cutting wheels that are less expensive, however, the number of different materials that can be cut with these wheels is more limited than that of the heavier-duty abrasive wheels.
The shape of the cutting wheel is another intentional factor in the manufacturing of the tool. The narrow disc shape helps the cutting wheel to slice into and through materials rather than dig into them, like that of a toothed saw blade. This allows for a smooth edge on the material being cut and makes the cutting motion easier due to the reduced surface-to-surface contact.
Cutting wheels are also available in different diameters, making them useful in a variety of construction and fabrication environments. When there are leftover tab ends on a chassis or any welded apparatus that must be removed for the next step in the fabrication process, the most efficient way to get rid of them is to cut them off with a cutting wheel. In construction, the cutting wheel is generally used on a smaller scale, often to cut the heads or the ends off of bolts, the heads off of screws, and the ends off of pipe fittings that require precision as well as clean cutting.