How often should we replace CNC tool holders and collets?


Question: How often should we replace CNC tool holders and collets?

We have been using the same tool holders (HSK 63) for multiple years, and I have seen recommendations to replace these on a yearly basis. That would be quite expensive for us, as we have many of them in use. What do you recommend?

As for collets, I usually replace them when edge quality becomes unacceptable. Is it necessary to replace them on a set schedule, or do most of you go by feeling?

Our advice:

Predicting the lifespan of a tool holder is extremely difficult. Various types of tool holders react differently to cutting forces, so frequent inspection is important. It is critical to clean and inspect tool holders and spindles after every job.

Tool holders should be completely disassembled and cleaned. A dust-free tool holder and machine spindle will ensure tool holders properly seat with maximum contact and are pulled into the spindle taper at optimum force. With holders held and positioned accurately, a machine’s full power can effectively and safely transfer to the cutting tools, and runout/vibration are reduced resulting in excellent surface finish quality.

If you see any Fretting (small rust colored spots on the taper) – the tool holder should be replaced, and you should also ensure the spindle is cleaned.

Collets should be replaced approximately every 3 months if being used 8 hours a day. When inspecting your collet, an easy way to see if there is metal fatigue is to insert the tool shank into the back of the collet and then try it in the front side. If the tightness is not the same both ways, then the collet is fatigued and should be discarded. One major cause of collet metal fatigue is from overtightening. The best way to ensure proper tightening is to use a torque wrench and a tool holder tightening stand.

Collets are manufactured from softer metal than tool-holders and feature special slots and cutouts allowing them to “collapse” and “spring” to tightly grip the cutting tool. As a result, they will wear out faster than the holders will.

Wood-Cutters Tooling offers a wide range of Tool Holders, Spring Collets, and a large variety of cutting tool options for most any application - we are here to assist you find the tools you require for improved production on your CNC machines. Visit our website: www.woodcutterstooling.com or give us a call at 616.257.7930