An F-clamp, also known as a bar clamp or speed clamp, is a type of clamp. The name comes from its "F" shape. The F-clamp is similar to a C-clamp in use, but has a wider opening capacity (throat). This tool is used in woodworking while more permanent attachment is being made with screws or glue, or in metalworking to hold pieces together for welding or bolting. An F-clamp is also a simple mechanical device used for lifting engine or transmission parts. The clamp has an adjusting screw to tighten onto the part and a lifting ring to attach a hoist cable. * * Bar clamps jaw detail *