hand-held machines with built-in compressed-air motors. They are designed for mechanization of manual labor in the construction, machine-building, metalworking, and mining industries, and also in transportation. The most common pneumatic tools are hammers, drills, concrete breakers, nut wrenches, saws, shears, grinders, and boring machines. Such tools usually weigh 2–10 kg and have piston and rotary motors with a power of 0.15–1.75 kilowatts (0.2–2.5 hp); the pressure of the compressed-air supply used with pneumatic tools is 0.6–1 meganewton per sq m, or 6–10 kilograms-force per sq cm.
Despite their comparatively low efficiency (10–15 percent), pneumatic tools are in wide use because of such advantages as safety, reliability, trouble-free operation, insensitivity to overloads, prolonged nonstop operation, and operation under conditions of dampness, dust, and explosion danger.