Wilton 21301 50, Forged Super-Junior C-Clamp, 0-Inch-1-Inch Jaw Opening, 1-Inch Throat Depth Super-Junior Clamps Are Forged Steel With Heat Treated Frames To Provide A Much Stronger Clamp Than Pressed Steel Or Malleable Clamps Steel Screws Are Zinc Plated For Longer Life Meets Fed Spec Ggg-C-406D, Type I, Class E Very Light Service