Tuesday, August 3, 2010

Are you installing your Collets correctly?

1. Snap collet into nut.

2. Insert cutter into collet.
Collets without counter bore require shank
to extend to the bottom of the collet.

3. Hand tighten collet nut assembly into tool holder.

4. Insert tool holder assembly into
tightening fixture and secure it.

5. Tighten collet nut to recommended torque
using a torque wrench and adapter.
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.  Be sure and check out our website and see the torque chart to make sure that you are getting the most tool-life out of your end mills and cutting tools.

A toolholder set-up fixture that easily mounts
to your Huot, Lista, or Rousseau Tool Cart 
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.

Under-tightening can also cause poor cutting performance, or allow cutting tools to fly out of the spindle – a very serious safety hazard.

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