Originally Posted by
bulgie
I'm 98% sure that's not true, Shimano axles are M10 x 1, a standard fine metric thread. 10 mm with 26 tpi (threads per inch) is obviously not a normal metric thread, it's a weird hybrid, that for some reason became the standard in Italy.
I agree that 10mm x 26tpi is truly weird and shouldn't exist. It was very frustrating when I was trying to find a solid axle for a parallax-era Shimano cassette hub, couldn't use an M10x1 axle, checked the cones on a gauge, and found that it was 10mm x 26tpi. I bought the nutted TX500 and was able to use its axle with the parallax hub's hardware, then rebuilt the TX500 with the QR axle from the parallax hub. This was three years ago, I mostly work on older bikes and don't know what Shimano's doing now, if they switched to standard metric axles then I'm glad!