V-Blocks are work holding tools that improve an operators ability to properly hold down a work piece. The sides, base, and contact surface must be precision ground so that the work piece can have reliable and sometimes repeatable reference surfaces on which to machine the work piece. V-Block must be checked periodically, heat treated, and precision ground to be an effective tool. holding tool. "V-Block" describes the surfaces in contact with the work piece. As such, whether it is round bar stock or square bar stock, the work piece uses both "V" contact surfaces to distribute the clamping forces so that the work piece can be machined in a fixed manner.