Hardinge HQC Quick-Change collets can be changed from one size to another in less than 20 seconds. The HQC System requires less draw bar force to adequately grip the bar, greatly reducing the breakage of closing fingers and pins common when the bar varies beyond the range of a standard solid collet or master collet with pads. Eliminating the need to change collets due to normal variations in bar stock, greatly reduces the downtime normally required. Since solid collets and master collets are of a one-piece construction, considerable force is required to flex the leaves of a solid collet and bring the gripping surface in contact with the workpiece OD. Because there are no leaves in the HQC system, additional gripping pressure is directly applied to the workpiece. Higher feed rates and higher spindle speeds are possible. Because of the extra gripping force, tool life increases and parts come off the machine quicker. There is no collet shank. Therefore, the collet segments remain parallel to the stock even when there are variations in the stock size. Parallel clamping minimizes stock "push back" and requires less draw bar force to achieve the same gripping capability as conventional collets. The HQC patented operator-replaceable slot-seal system eliminates the need to return the collet to the manufacturer to have the seals changed.