Pneumatic clamping fasteners are designed for quick change applications. Instant pneumatic clamping reduces setup time in multiple-parts holding and frequent changeover of machinery or fixture. These pneumatic holding clamps hold the internal diameter of prepared hole of a workpiece. These ID fasteners clamp when air is supplied, and unclamp when air is released. The pulling shaft goes down by air supply from clamping port and the jaws expand to hold the workpiece, with clamping contact with the workpiece at three places. The maximum clamping diameter is 22 mm. The holding force in the table is with 0.5 MPa air pressure and an 304 stainless steel workpiece (surface roughness Ra1.6). The body is made from 304 stainless steel. Pulling shaft is made from 420 stainless steel with an electroless nickel-plated finish, quenched and tempered. Includes two stainless steel socket head cap screws.