ER20 collet nut tightening torque / tooling?

(Julien Heyman) #1


So far I have been tightening my collet nuts “monkey tight, not gorilla tight”, and it has worked out nicely. Now that I use ER collets with super low runout, I am wondering if I should be a bit more accurate than this, and have some specific tooling to make sure I apply a controlled and repeatable torque on the collet nut.

I read somewhere that the recommanded tightening torque for ER20 collets is 59 ft/lbs.

What’s a cheap option/tool to do this ? (bear with me, I’m not a machinist or even a mechanically-inclined person, the answer may be as simple as “get a wrench of just the right length, you doofus”)

EDIT: oh and by cheap I meant much less expensive than this


(Pete) #2

If you already have a torque wrench maybe you could cut a “head” that fits the socket drive end similar to that expensive wrench you posted?

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(Luc) #3

How about using something like this crowfoot wrench attached to a regular torque wrench

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(Luke (Carbide 3D)) #4

I have never used any special tooling to tighten my ER20 collets. Nor have I had a problem…


(William Adams (Carbide 3D)) #5

Hmm, 14 ft. lbs. for ER11:


(Julien Heyman) #6

Yeah probably overkill, I agree. But it’s always good to own one of those gismos that makes you feel/pretend like you know what you are doing :slight_smile:

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(Julien Heyman) #7

@WillAdams thanks, the ER20 model is still 66$, much better but still above my arbitrary psychological price threshold.
@Winters636 and @luc.onthego this makes sense, I don’t own one but I looked and I could buy one in the low 30$ range, and then “just” change the head indeed.


(Jim Beins) #8

If you do use a crows foot or anything that extends the arm of a torque wrench, you will need to do a mathematical formula to ensure you are getting the correct torque. I used to know them, but Im sure if you search google for torque wrench offset it will pull some examples up