Clamps & Vises structure are simple, easy to use, fixed clamping plate is to rotate the clamp body around the screw to adjust the lower end face of the upper part of the clamp body and the tight surface of the plate at the top of the screw and the distance applicable to the thickness of the clamp plate, the plate is placed in it, and the handle at the bottom of the rotating screw makes the screw rise to tighten the plate.