A concrete saw (also known as a consaw, road saw, cut-off saw, slab saw or quick cut) is a power tool used for cutting concrete, masonry, brick, asphalt, tile and other solid materials. There are many types ranging from small hand-held saws, chop-saw models and big walk-behind saws to other styles, and it may be powered by gasoline, hydraulic or pneumatic pressure, or an electric motor. The saw blades used on concrete saws are often diamond saw blades to cut concrete, asphalt, stone or other hard surfaces. Abrasive cut-off wheels can also be used on cut-off saws to cut stone and steel. The significant friction generated in cutting hard substances like concrete usually requires the blades to be cooled to prolong their life and reduce dust.