Frames are made from high-strength ductile iron castings Black oxide coated ACME threaded spindles resist wear and tear while impeding rust Oscillating ball and socket tip centers on the workpiece allow for a great grip Ideal for light industrial, woodworking, and repair applications Set includes: 2-1/2" c-clamp (22001), 4" c-clamp (22003), 6" c-clamp (22005), and 8" c-clamp (22006) Backed by Wilton's industry-leading lifetime warranty against manufacturing defects