The ch hanson manual locking c clamps are made from high grade alloy steel with a nickel plated finish for maximum toughness and durability features a traditional release lever which allows the clamp to be released even at a high pressure the traditional adjustment screw allows the clamp to fit to various sizes and pressures meets all asme product specifications models 71120 71825 are fitted with swivel pads that provide a greater surface area of contact to hold material in place