Collets are used with Expanding Mandrels or with Arrangements for Contracting. Expanding & Contracting arrangement for collets consists of several integrated parts which makes it a total self-operative unit. Depending upon the nature of operation to be performed on the work piece, the expansion or contraction is achieved through a inter-related series of parts like drawbars, expander / contractor housing, face plates, clamps, job rest pads, spring loads, centers, sleeves, segmented taper wedges, locking pins etc. Designed in terms of metallurgy & geometry considering the type of machining operation and expected force generation on the work piece. For Eg:In a grinding collet, where a repetitive collar grinding operation is done, the geometry of collet assembly is critically and skillfully controlled so that each job is located and clamped by the collet in same position within accuracy in microns, thereby saving time in machine setting achieving higher productivity & uniform quality.