An abrasive saw, also known as a cut-off saw or metal chop saw, is a power tool which is typically used to cut hard materials, such as metals. The cutting action is performed by an abrasive disc, similar to a thin grinding wheel. The saw generally has a built-in vise or other clamping arrangement, and has the cutting wheel and motor mounted on a pivoting arm attached to a fixed base plate.
They typically use composite friction disk blades to abrasively cut through the steel. The disks are consumable items as they wear throughout the cut. The abrasive disks for these saws are typically 14 in (360 mm) in diameter and 7⁄64 in (2.8 mm) thick. Larger saws use 410 mm (16 in) diameter blades. Disks are available for steel and stainless steel.
Since their introduction, portable metal cutoff saws have made many building site jobs easier. With these saws, lightweight steel fabrication previously performed in workshops using stationary power bandsaws or cold saws can be done on-site. Abrasive saws have replaced more expensive and hazardous acetylene torches in many applications, such as cutting rebar.
Cutoff wheels are composed primarily of fibers, held together with a group of small particles pressed and bonded together to form a solid, circular disk. Materials used are generally silicon carbide and diamond bits with a vitrified bonding agent.