Gday Stefan
You mean something like this
https://www.thorlabs.com/thorproduct...number=AS25E6M
What i normally do for one offs like this with oddball thread sizes is buy/make a coupler union, then thread a bolt into it and then use a die to cut the external thread into the the oversize shank of the bolt,
but for $4 plus postage, the link above cant be beaten.
Andrew