Why didn't I think of this !!!!
I was at a buddy's shop today & he was explaining how he set-up front and rear wheel bearings. He told me he assembled the spacer, bearings,etc... After that he took a piece of all-thread the right size & length and used it for his new axle.Then you use SAE flat washers ( because they are narrow) and nuts, you assemble and torque the nuts to 50' lbs. If the bearings spin freely everything is o.k... If not it is time to do something. Either a new spacer or tapping e.g. seating the wheel bearings into the hub for 0 lateral pressure because roller bearings cannot tolerate this.
When installing bearings you want to make sure the bearing is seated in the hub and against the spacer. That is why you are doing this to make sure NOTHING happens on the road !