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