1200Kg capacity. Tempered steel sliding arm. Drop forged, electro-galvanized. Rail, Fixed jaws and pressure plate heat-formed in one piece from cold drawn profiled steel, optimized for high static stress loadings. Heat treated, high carbon ACME threaded screw is tempered and quenched to give to give you greater loading capacity and longer service life. Spatter resistant. Throat depth 5-1/2"