1/4" Malleable Iron Beam Clamp, -20 Threaded Openings, Fits Flanges Up To 1-5/16" Thick, Supports Threaded Rod, Threaded Brindle Rings & Electrical Boxes, Malleable Iron With Electroplated Bright Zinc Plating, Set Screw Load Rating 250, Static Load Limit 250 LB, Based On A Safety Factor Of 3, Load Rating Based On Bottom Hole Of Beam Clamp, Torque INLB 60.