The diaphragm principle as applied to chucking utilizes the inherent strength and accuracy of spring steel to achieve chucking pressure on internal or external surfaces. Applications of this principle have been production proven. Diaphragm chucks are used primarily for secondary operations, such as grinding, boring facing and light turning. Locating surfaces should be pre-machined or a precision cast surface.

How a Diaphragm Works!
Air is introduced through the spindle and adapter plate by means of a ¼" pipe. When air pressure is applied, the piston moves forward about .030" and the movement is transmitted to the diaphragm by a push sleeve. As the diaphragm is flexed, the jaws open and the workpiece is loaded. To chuck, the air is turned OFF, and the jaws move toward the relaxed position until jaw contacts the part. Part is located on center. Consistent concentricity is controlled to a maximum runout of 1/3 of the part tolerance.