Originally Posted by
JoeTBM
If this is a used spindle from ebay, they may have used the wrong tool to pull the crank and damaged the threads inside the spindle. As others have said, is is a M8 x1.0mm. Good luck with using a tap, the spindles are hardened steel.
It is supposedly new, and the cups s and bearings look new, but I suspect the spindle is "refurbished". Seems to have been coated with something that made the threads unusable. I could be wrong. It's not worth returning, so I'm going to mess around with it. I'll post an update and some photos when I've got it fixed or destroyed.