L.H. Dottie BK38 Beam Clamp, 0.781-Inch Jaw Capacity, Zinc Plated, 25-Pack Beam clamp in made of zinc plated steel Case hardened steel bolt Tapped threads back and bottom Features 3/8 inches - 16 TPI Comes in 6.62 pounds weight Zinc plated steel Case hardened steel bolt Tapped threads back and bottom 3/8-inch-16 TPI 6.62 lb. weight