[Travis Covington]

We have made shafts similar to these since 2007. The 2006 shafts were slightly simpler and didn't have the 5/8" hex. Each year the shaft changes slightly as well, usually to accommodate differing gearbox configurations, wheel width changes, etc.

The tolerance on the hex portions of these shafts is +-.0005, but that may be overkill depending on the precision you require and the amount of slop you deem acceptable.