Jorgensen steel bar clamps are seriously strong (clamping force 1,000 lbs.). Cast-iron stationary and sliding heads with an orange, powder coated finish are merged with a high-carbon, rust-resistant steel bar that packs a whopping 80,000 pounds per square inch of tensile strength. The fast-acting sliding head is acme threaded to accommodate a cold-drawn steel screw with a large easy-grip handle and swivel pad. And the original multiple-disc-clutch design allows the sliding head to hold securely