The Simple Way to Prevent Loose Joints
Lock Washers (or more properly, helical spring lock washers) look like they are broken, but are actually very short coil springs. In use, they increase a bolt’s clamping force (per unit of applied torque) and help prevent loosening due to vibration, among other things. In general, if a bolted joint is supposed to clamp materials together, adding a lock washer is worthwhile. Lock washers must be used in combination with a flat washer to be effective. Imported.