Review on Ultimate Strength and Durability: Aobbmok Solid Steel Plated Collars - Unmatched Performance for Serious Lifters by Johnny Pigao

5/8 clamps are a meager .6255 ID. Had to drill them out to use them on a wheelbarrow axle. I have access to the necessary lathe. If you don't do this, make sure the shaft you plan to mount it on is at least 2-3k undersize and free of burrs or dents. A build that should have taken five minutes took me an hour longer.