Are you installing your Collets correctly?

Installing ER (DR, RD, ESX) , style collets is very common in every machine shop and tool & die shop, but is everyone doing it CORRECTLY?

Did you know that there is a torque specification on your collets?

Many people use a cheater bar to tighten down collets believing that the "tighter is better" but that's not always the case.  Like all toolholding collets, ER style collets are spring collets with a 30 degree front taper and a 16 degree back taper (a "free releasing 'locking-taper" just like your steep taper toolholder) 

​When the 16 degree taper "locks" and you continue to over-torque the collet nut, the collet can twist and, under the normal load of cutting conditions, the cutting tool will run-out.  

We also recommend using a tightening fixture and torque wrench to make sure cutting tools and retention knobs are properly tightened.

Over-tightening can distort or even crack collets, causing runout problems and premature failure of the collet, nut, tool holder and cutting tool.
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Under-tightening can also cause poor cutting performance, or allow cutting tools to fly out of the spindle – a very serious safety hazard.