1　Put screws or bolts through the inner rings of the appropriate types of washer for the machine. Use a Belleville safety washer to prevent a bolt from loosening due to vibration. Select a Belleville heavy-duty bolting washer to prevent a bolt from coming loose on a machine that experiences repeated expansion and contraction, or choose flange bolting washers to fit into a sunken flange under a bolt head and protect against loosening from contractions and expansion.

　　2 Thread the bolt or screw with the Belleville washer into the appropriate fitting on the machine. Place a nut behind the bolt if it doesn't sink into a threaded machine part. Place a Belleville washer under the nut before tightening as well.

　　3 Tighten screws with a Phillips or slotted screwdriver; secure bolts with a wrench. For machine parts that demand a specific torque, or bolt tension, use a torque wrench to tighten bolts to the specified torque. Line up the specified torque figure to the setting line on the handle of the torque wrench and tighten the bolt until the wrench clicks and lets go of the turning tension.