The Pony Jorgensen 4 Piece Steel Bar Clamp Set from ITS is crafted from cast iron and high-carbon steel, these clamps boast rust-resistant properties, ensuring reliability in various applications. It is a sliding head design the sliding head is threaded to accommodate the screw with large easy grip handle and swivel pad. The sliding head features a multiple disc clutch design, allowing for secure holding at any point along the bar. With a maximum opening of 150mm 6 and 300mm 12, and a clamping force of 272kg 600lb, these clamps provide sturdy and reliable support for your woodworking, metalworking, and DIY projects.