Air-powered impact wrenches, torque wrenches, and ratchets connect to a compressed air supply to turn nuts and bolts. These tools have a square drive for holding interchangeable sockets that fit the fastener to be turned. Air-powered tools are lighter than corded and cordless tools and typically require less maintenance since they have fewer moving parts. They speed fastening and reduce user fatigue compared to hand wrenches and ratchets. Air impact wrenches use impact-rated sockets and combine a hammer-like impact with high rotational torque to drive and remove large or frozen fasteners. Air torque wrenches use gear reduction rather than an impact mechanism to apply a predetermined amount of torque to fasteners in applications where overtightening can damage parts. Air ratchets have compact heads for working in tight spaces and allow precise control of positioning and rotational torque in applications where high torque isn't required.