Sometimes it is next to impossible to find the size bearings you need so you have to make them
Shown below is a 28 inch diameter bearing set for a jib crane
the way the races are machined the inner race fits around a H beam and has a 90°contact area for the balls
the outer race still in the lathe has a 90° contact area as well but is the opposite of the inside this way the bearing was not only 100% thrust capable but 100% radial as well Not like the angular contact bearings that can be bought off the shelf
the material was ASTM 514 T1 steel later it was surface hardened.