Review on 🔧 SOLEJAZZ Heavy Duty Retractable Workbench Caster Kit - 880 LBS Capacity, 3" Urethane Wheels, All Steel Construction, includes Bonus Install Template - Pack of 4 by Thimothy Purnell

They're pretty durable so I don't think this will be a problem. Replaced the cross bolts with 5/16 and used 1/4 machine screws since they attach to the tubular steel post. The cross bolt holes in the bracket were already 5/16 and the mounting holes were already 1/4 but holes for the arm/pulley plate had to be drilled to 5/16. I'm not sure what type of scrap they're made from, but it's very hard and I ended up using an end mill instead of a drill. Time will tell if they hold up. I think if anything will fail it's the wheels themselves. Other reviews like this one mentioned that the wheels break and they also appear to have a hard plastic core. I like their general idea, but if what you have them on has any kind of stiffness, squeezing one of them will put all the weight of that side of your table/bench on that single pulley. And depending on the weight distribution, your table/bench can easily tip over until you can use the other one.