Good day everyone. I am kinda new at this so bare with me. I have a 2.2kw perske 20krpm spindle , for wood i know, but i thought the metal forum would more likely know the answer to this. The spindle has an er16 collet. I am buying collets for it and and i am told there is no 1/2 in collet, but i also am told there is a 13mm collet. Does anyone know if it is ok to use a 13mm er16 collet for 1/2 shanks? Or would i find a 1/2 er16 collet some where else?

i don't know for sure, cause i've never tried it - but the collets usually specify a range that they can be used for.

for example an er20 1/2" collet has a range of 0.47-0.51

so you might be in luck, clamping a 1/2 bit in a 13mm collet. 13mm = .511"

If you can get a 13mm ER16 collet it will probably squeeze down to 1/2"; 13mm is only 12 thou larger than 1/2" and ER collets are supposed to have a grip range of almost 1mm which is 39 thou.

But I think it might be a big 'if'; 13mm seems very large for ER16 and there would not be much material in the collet.

Thanks you for the replys but i think i was mistaken. er16 does not go to 13mm. Max is 10mm. Ideas on some how making use of my 1/2 shank bits anyone?

You'll need to use a solid tool holder for bits larger than 3/8" (10mm). I carry the A2Z tool-holders: http://soigeneris.com/A2Z_ToolHolder.aspx . Your bit mounts into the holder with a set screw and you screw the holder on in place of the collet nut. One benefit of them is that they give you a very reliable tool offset (Z) between tool changes. If you have a few larger bits that you use a lot it is more convenient to have a holder for each and then they are always ready to go.

Shipping small parts like this via postal service is pretty reasonable too.

Thanks - every one I have ordered a er20 collet extender. I already had the er20 collets from another machine.

Still having trouble. I bought these endmill holders, the perfect solution but they dont fit the Perske spindle. Collet nut is 19mmX1.0 So the imperial end mill holder will not fit on this spindle. Any other ideas anyone please. This whole excersize is taking on epic envestment in time.