Yoyo Axle thread sizes


Does anyone know anything about the threads on the axle. I am looking to machine some yoyos and will be drilling and tapping the axle hole. I have not picked which axle will be used, but I am curious if anyone knows what some of the common ones are.

Maybe they are 4-40 threads, or 2-56. If you know that would be helpful so I can make sure I have the correct tap sizes.



I believe there’s a list of common sizes here…
List of useful modification and maintenance guides

The minimum useful size is generally a #6. Currently #8 & #10 are used some. 1/4-20 used to be popular. On the metric side 4mm x 7 pitch is common.