.25" ER-11 Collet and Nut

Hi all,

Need to get my hands on a .25" ER-11 Collet and Nut before my Nomad arrives but everywhere is out of stock even on the carbide site so my question is can you buy an after market one that will fit the nomad? Is the ER-11 nut a standard size or does the thread vary? UK based so would prefer a UK supplier


ER is a de facto standard, so any ER-11 collet ought to fit.

I bought some nuts and collets and a wrench from Maritool:


and was quite pleased w/ them. Planning on getting a full set of metric collets and the castle nuts to differentiate them from Imperial when I have a job which warrants it.

Another option is Precise Bits:


which are available in an assortment of precision grade to match your work and budget.

I usually get collets (ER11 & ER20) from here in the UK but they don’t tend to stock 1/4” and are more metric-focused.

If you can work with 6mm instead, you might have a larger local range of options.

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Some collets are sold with a 0.5mm clamping range, so you can get a 6.5mm metric collet and use 1/4" endmills while remaining within spec. Make sure that the collet is specified for that clamping range though, many are only suitable for the nominal diameter.


Arc seems to have a range in all the glorious fractional irrational number sizes (as well as decent metric ones ;- )


I’ve used them before, they’re a decent supplier. Their ER collet nuts are not balanced for high speed spindles though so you want to find another supplier for the nut. I have not been able to find a decent supplier in the UK for balanced ER20 collet nuts yet, I’ve been taking AliExpress pot luck, buying bags of 3 “precision balanced” and throwing away the two worst ones.

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Have you tried Rennie Tools?


There was a list of known suppliers that people here had used on the Wiki, see this thread

I don’t seem to be able to find the tool suppliers on that page of the Wiki any more though, has it been reorganised @WillAdams ?

Not reorganised, trimmed on request by the powers that be.

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Wayback Machine to the rescue!

And if “the powers that be” are going to remove useful information from the wiki, maybe we need to copy it somewhere outside their control. Maybe @Julien’s book?

I noticed the page about the Shapeoko e-stop had been removed too.



It could be worse


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