Without breaking out the micrometer - rear axle is 20 millimetres. Front is 25. That'll be 25/32 inch and 63/64 inch if you're reading this in black and white.
Michelle, are you certain about that? I know the shoulder {at the ends of the front axle} are larger, but I thought the Inside diameter of the bearings were the same?
Ride safe, Ted
Update; Michelle; I looked at images on Ebay and I think you are correct. kzz1king; What are you thinking to do? I'm wanting to do something similar to my HF tire changer.
Dimensions - d (inside diameter) 25mm Dimensions - D (outside diameter) 47mm Dimensions - B (width) 12mm
REAR 601B6304UU BEARING-BALL,#6304UUC3
Dimensions - d (inside diameter) 20mm Dimensions - D (outside diameter) 52mm Dimensions - B (width) 15mm
with that said, and to make the H/f tire machine happy, you want a 3/4" threaded rod, which will work on both wheels just fine. The H/F I have, is actually threaded 22mm, but a 7/8" bolt, with a wrap of teflon thread tape, will thread into it... I made a screwed in adapter for mine, and a pals, by elding a 3/4" SAE nut, to the head of a 22mm bolt, and it allows me and him to insert a piece of 3/4" all-thread, to use as a center post... with common nuts and washers.
Update. Following Mobs direction on HF mods improved the process tremendously. I used to just stick a old lug wrench in the center. The Mojo lever likes the solid center much better. Great mod.