Faithfull heavy-duty clamps manufactured from a high-quality carbon steel bar with large malleable iron clamping heads. Clamp bars have a black oxide coating with powder-coated heads for complete rust protection. Other features include a high grade steel mainscrew with a wear resistant Acme thread, which applies pressure quickly and smoothly. Tail slides are easily adjusted and secured by a steel pin passing through one of the locating holes. Tail slide and heads are flat bottomed so that the clamp can stand upright without support.