Heavy duty, low profile machine moving skates/dollies, with a solid roller “bushing” type design, (no ball bearings to fail). I use all American made steel that is locally sourced, and the skates feature all Grade 8 hardware for maximum strength. Each roller is made from solid steel, which is turned on a lathe for concentricity, drilled and bored, and then finish reamed for a close tolerance fit onto grade 8 shoulder bolts. A light coating of grease is all that is needed for smooth operation. This creates a much stronger and more reliable design than ball bearings. High load applications should always use bushings, not ball bearings that can fail under extreme load due to point loading. Bushings can handle much more weight than bearings, because the load is more evenly spread over the entire surface area of the bushing, vs the point loading of ball bearings. The 2.25” inch wide solid steel rollers are fully contained within the undercarriage of the skate, putting all of the weight straight down, preventing any flex in the axles. The skates only stand 1.75” high, which make them very easy to get underneath any machine, and the top side is threaded for a mounting bolt to secure them to the bottom of a machine and keep them from slipping out while moving across uneven floors. I personally make each and every one of these skates by hand, using all manual lathes and mills in my small home machine shop in Ohio This listing is for one (1) skate. Thanks for looking!