58 Piece Clamping Kit for a 1/2" T-Slot ~ Stud size is 3/8"-16 ~ Made of powered casting steel for stronger strength. ~ All parts are heat treated. ~ Includes 4 each of 3", 4". 5" and 6" studs, 4 coupling nuts, 6 flanged nuts, 6 forged steel step clamps, 6 t-nuts, 12 steel step blocks and 1 wall rack.