I'm building up a boost spaced mtb. I have a DT Swiss 12x148 thru axle for the rear wheel. It won't screw into the derailleur hanger threads so I assume the thread pitches are different. What do I need to know about this? Thanks!

What frame is it? as this will define the thread needed/brand/model needed on the axle for your frame, and why can't you use the axle that came with the bike, at least you will know that this fits?

Derailleur hanger threads are 10x1mm. What were you expecting to learn by trying to thread a thru-axle into it?

There are three possible thread pitches for a 12mm rear thru axle. 12 x 1, 12 x 1.5 and 12 x 1.75. There are also varying lengths based on what standard the frame manufacturer used. All "boost" frames do not take the same length axle.

All About Thru Axles - Fairwheel Bikes Blog

A lot of thru axle frames have the axle thread integrated into the derailleur hanger and it does double duty as both the hanger and the thru axle nut.

Oh, the mount for the derailleur hanger? Got it.

In addition to overall length, you also need to match the length of the threaded section of the axle. Too short is bad as the axle threads could bottom out before the hub is fully clamped in the frame. I don't know what happens if the threaded length is too long. It's probably okay up to a point.

At least, that's the way it works for non-boost frames. Maybe the industry did a better job of standardization with boost, but I doubt it.

Hey, I am looking for the same solution. Have you got any reliable person for this job?