Drop forged and through hardened from alloy steel for a stronger, tougher, and longer lasting tool Threads are roll formed for greater strength, smoother running, and more clamping force with less effort Patented design pad completely encircles the ball of the screw providing permanent attachment and full swivel action Extra throat depth provides greater versatility when working with larger objects Proudly made in the USA with a lifetime warranty, Weight: 12.69 lbs., Manufacturer: Armstrong