A concrete saw (often known as a consaw or road saw) is a power tool used for cutting concrete, masonry, brick, asphalt, tile, and other solid materials. It can be a small hand-held cut-off saw, a big walk-behind saw or other styles, and it may be powered by gasoline, hydraulic or pneumatic pressure, or electric motors. The saw blades used on concrete saws are often diamond saw blades to cut concrete, asphalt, stone, etc. 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.