FlexC Vulcanized Collets

You've probably heard the term "vulcanized collet" and may have wondered what it means exactly. Vulcanization was named after the Roman God of Fire, Vulcan, and, yes, the injection molding process at Hardinge does involve heat. Vulcanization is a chemical process for converting rubber or related polymers into more durable materials, in this case, vulcanized rubber that permanently bonds hardened, chrome-nickel steel collet sections together. Why do we need vulcanized rubber in a collet head? Vulcanized rubber has superior elasticity for repeated opening and closing of the collet without deterioration.

Now that we have established an elastic design, a manual wrench can be used to compress the collet providing quick changeover in seconds instead of minutes! Add up all of the minutes saved and that equals reduced manufacturing cost. Quick changeover is not the only benefit you'll experience. The FlexC collet system proudly falls in the "special accuracy" collet classification having guaranteed accuracy within .0004" (.010mm) TIR for both collet system styles A (pull-back stationary stop) and D (pull-back thru-hole) and .0008" (.020mm) TIR for style DL (push-to-close dead-length).

These systems achieve the same gripping capability as conventional collets while using less draw bar force. Additionally, the all-too-frequent variation in bar stock will no longer be a hindrance. The collet head has a gripping range of +/-.020" (.5mm) of its nominal size to allow variation in bar stock 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 bar stock. This parallel clamping minimizes stock "push back" that could create inconsistent part lengths.

Hardinge FlexC 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. Hardinge stocks 42 and 65mm collet sizes in round smooth and serrated styles. Hex and square sizes are made to order. Some examples of custom-manufactured applications include stepped holes, special shapes and off-center work. An added bonus is the fact that FlexC collets can be shared with vertical machining centers using Hardinge FlexC Collet Blocks.

These modular collet blocks are compact with a low profile for increased axis travel and can be used on 5th-axis rotary trunnions as well. Whether it's a single part or a multiple-part setup, this system provides a solution for gripping parts in many shapes, sizes and materials. The Hardinge FlexC Collet Systems are ideal for the job shop environment where machines experience multiple changeovers daily, and stock variations occur. The quick collet changeover can increase output and lower manufacturing costs, while the special accuracy could qualify that machine to handle a wider variety of jobs. Test results from repeated collet actuation indicate a highly durable, fully sealed gripping solution.