These casters work as advertised although I think 150# per wheel might be a bit risky. /2 screws. Those 3/8" bolts on these 4" casters feel a bit flimsy for a 150# rating. I guess it depends on what you're using them for, but for my (heaviest) smoker, they can squeeze. Remember, when you place your bench, counter, grill or whatever you put on it, the casters will experience a lot of lateral pressure as the casters rotate in the direction of travel. If you need casters for the room, you can consider others. The smell of it will blow you away when you open the sealed plastic bag. It smells very strongly of cigarette smoke.