Heavy duty, low profile machine moving skates/dollies, with a solid roller “bushing” type design, (no ball bearings to fail). I use all American sourced steel that is locally sourced, and the skates feature all Grade 8 hardware for maximum strength. Each roller is made from solid chrome-moly tool steel, which I lathe turn for concentricity, drill and bore, and then finish ream for a close tolerance fit onto inch diameter 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 cheaper units that use 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 spread evenly over the entire surface area of the bushing, vs the point loading of ball bearings. The 2” 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 are very low profile and only stand 1.75” high, which make them very easy to get underneath any machine for moving, and the top side is threaded for a mounting bolt to keep them from slipping out while moving. I personally make each and every skate by hand, using all manual lathes and mills in my small home machine shop in Ohio. This listing is for two (2) skates. Thanks for looking!