Any loose ball bearing hub I ever encountered since I started playing with bikes in the 1970s has a threaded axle. From the lowly department store bike to top end race bikes. Sealed bearing hubs have press fit bearing cartridges and do not need threads to install. There are always a few exceptions to every "rule" if you look hard enough.
In order for it not to have threads in the dropout area, they would have to machine down the diameter so the cones & nuts could get to the threaded area. Extra work for no benefit.
Originally Posted by
1989Pre
My Royce hub has a piece at either end of the axle that slides into the dropout.
It is flat on both sides and the fit is exact.
From my 30 second investigation of Royce hubs, they appear to be sealed bearing hubs. The majority of hubs (of all quality levels) , were loose bearing hubs "back in the day".