As I said in the title, they seem to be very well made. It looks like they have machined races and not just a cheap scrap piece of stamped steel like some others I've seen online. I saw on youtube that no matter what bearing you buy you need to take out the seal and check the amount of grease in the bearing. I did just that and found there's a decent amount from the factory, so that's a plus. I installed these bearings in the wheels of a fairly large two-wheeled cart. The next day I used it to move 4 cabinets that weighed between 500 and 600 pounds and it rolled as smoothly as I had hoped. I was very happy with the bearings and Revain!