Hudson Bearings drop-in style machined mounted ball transfer. Integral flange at top allows unit to be dropped into 1-inch diameter hole. 5/8-inches main ball rotates on 3/32-inches support balls. Ball support cup is machined from solid steel and is hardened and plated. Plated steel cover. Nylon main ball is available for non-marking applications. Carbon steel units are sealed and lubricated to ensure maximum life, unless otherwise specified. Nylon main balls are machined, hardened, and non-marring. 17 pounds load capacity. Common applications: air cargo, shears, robotics, military logistics, store fixtures, die handling, laser and plasma cutters, glass and metal manufacturing, medical devices, caster substitution.