Thread: ER20 collets for my router

How many bits are you likely to run that can't be found in 1/4" and 1/2" shank?

Collets, Nuts and Toolholders

Using the E20 collets allows the use of cheaper end mills.

Originally Posted by elanjacobs

How many bits are you likely to run that can't be found in 1/4" and 1/2" shank?

I mainly want to have choices.
I also use metric bits and want to use solid tungsten bits.

From what I can find, with 1/2" shank ER collet extensions you're limited to ER11, so < 8mm shank size bits. I guess you could get the shaft on something bigger milled down to 1/2" though. As you've mentioned the shaft length on these extensions can be a problem, but they could be shortened to give an overall length of say 60mm.

Can you use an ER collet nut directly on your router? I use Makita routers and I know that 20 x 1 ER 16 collet nuts are available that screw straight on to the router. I believe that you don't need anything other than the nut to safely use the ER collets, but I'm no expert so correct me if I'm wrong.

Originally Posted by aldav

I believe that you don't need anything other than the nut to safely use the ER collets, but I'm no expert so correct me if I'm wrong.

Surely that would only be if the existing taper on the router shaft matches the ER collet taper

Thanks for that Elan, I'm sure you're right.

A further search has turned up some ER 16 straight 1/2" shanked tool holders, for example - https://www.maritool.com/Tool-Holder...duct_info.html

Thanks for your replies, I have found 'extension ER20 collets' and they are fine but ideally a shorter option like in my post would be better or even better screw the collet straight to the router - but I dont believe the taper is compatible?
If I could read somewhere what the tapers are on my exisiting routers are I might be tempted!
Otherwise I thought the shorter 'bolt on' collet might be best?

What is your router?

what am I missing here?

ER collets and metric shanked bits are "industrial" -- i.e rather specialised and relatively expensive for a home hobbiest.
but the OP would like to use these in a low cost router

something seems out of wack.


perhaps Elan can comment

As the OP has stated above he is hoping to use a range of sizes of solid carbide endmills. Unlike conventional 1/4" and 1/2" shanked bits they tend to have a shank diameter the same as the cutting diameter (well those above 3mm shank size anyway). Because there's no material wastage, and minimal machining of the bit required during manufacture it is possible to buy a high quality bit for a very attractive price.

Just found this - Elaire Corporation -Router Collets

They make collets that fit the standard nut for 5 different brands of routers. They're well reported on in any posts I've found on them. Could be another option.