Hardinge Inc. supports European-style, multi-spindle machine owners in North America. They manufacture and inventory solid collets, master collets & pads, solid feed fingers and master feed fingers & pads for Euroturn, Gildemeister, Index and Schütte machines with 24-hour shipping of standard fractional and whole metric sizes. Decimal sizes and products for other brands of machines will be available within a 5- to 7-day delivery. Hardinge institutes a semi-finished blank program for fast turnaround of pickoff burring collets and special-shape collets.
According to Hardinge, the collet should match the bar stock exactly. If you use inch bar stock, you should use fractional collets–NOT metric. Very few metric sizes have a direct fractional equivalent. Metric collets for metric bar stock, fractional collets for inch bar stock, and decimal collets for decimal bar stock will provide the best results. Match the collet size (order hole) exactly to the workpiece or bar stock diameter. If you are using ¼-inch bar stock with a 6mm collet, you could get push-back, chatter or poor concentricity because the collet is smaller than the bar stock