sheet metal grip better toughess G clamp because of its welded 2 layer carbon steel body,powder coating zinc plated screw sheet metal gripmaterial:welded 2 layer carbon steel ,powder coating. Cast iron clamp is easy to break ,yet our G clamp works with better toughness.color could be changed as you need.screw:zinc platedsize:2",2.5",3",4" sheet metal grip,g clamp,c clamp