Adjustable C-Clamp is cold-drawn steel with special and smoothly rolled threads. Its features are ductile/malleable iron frame, bright plated finish on frames, swivel is securely fastened to screw & revolves freely and machine-ground anvil. The cross pin at the channel entry end engages one of a plurality of grooves in the top of the first member To adjust the extent of the inner member from the outer member, it rotates out of the channel to separate the pin from the selective groove, allowing the inner and out members to adjust their relative position.