Vulcanized Collet Systems

According to Hardinge, vulcanized rubber has superior elasticity for repeated opening and closing of the collet without deterioration.

According to Hardinge, vulcanized rubber has superior elasticity for repeated opening and closing of the collet without deterioration. Now that the company has established an elastic design, a manual wrench can be used to compress the collet, providing quick change-over in seconds instead of minutes. Add up all of the minutes saved and that equals reduced manufacturing cost.

The company’s FlexC collet system falls in the “special accuracy” collet classification having guaranteed accuracy within 0.0004" (0.010-mm) TIR for both collet system styles A (pull-back stationary stop) and D (pull-back through-hole) and 0.0008" (0.020-mm) TIR for style DL (push-to-close dead-length), the company says. These systems achieve the same gripping capability as conventional collets while using less drawbar force. Also, the variation in barstock will no longer be a hindrance. The collet head has a gripping range of ± 0.020" (0.5 mm) of its nominal size to allow variation in barstock without having to change the collet.

Because there is no collet body, the collet segments will remain parallel to the stock even when there are variations in the barstock. This parallel clamping minimizes stock pushback that could create inconsistent part lengths.

These collet systems are compatible with many CNC lathes and are interchangeable with other brands on the market. Substitute a FlexC collet system for 16C, 20C and 25C collet applications to meet special accuracy requirements, or mount it on a chuck-style lathe or rotary indexer for increased versatility. The spindle mount will fit on A2-5, A2-6, A2-8 and some flat back spindles (main and sub). Once the FlexC spindle mount is attached, different collet head sizes can be interchanged from job to job.

The company stocks 42-mm and 65-mm collet sizes in round, smooth and serrated styles. Hex and square sizes are made to order.

These collets can be shared with vertical machining centers using the company’s FlexC collet blocks. The collet systems are especially useful for the job shop environment where machines experience multiple change-overs daily, and stock variations occur.