High quality wooden Hand Screw Clamps made for us in the USA. The screws have an acme thread, which allows for high strength, low thread friction with close tolerance, and rapid reliable operation. All metal parts have been plated to prevent rust. The jaws and handles are made from hard maple and feature heavy steel ferrules pinned to the spindle with an extra heavy spirol pin. The spindles and swivel nuts are made of cold drawn carbon steel for high tensile strength. With a deep throat, the jaws can apply pressure over a broad area or to a specific point. Materials: Hard Maple Jaws & Handles, Acme Thread Screw, Cold Drawn Carbon Steel Nuts, Steel Ferrule.