Hudson bearings nmbt-5/8cs 5/8 nylon ball carbon steel machined drop-in ball transfer 5/8 inch nylon main ball rotates on a bed of 3/32 inch carbon steel support balls in a carbon steel machined cup. The cup and cover are hardened and zinc plated. Hudson bearings is an innovative domestic manufacturer of ball transfers. the mbt ball transfer features a machined housing that is hardened and plated with a stamped metal cap. integral flange allows unit to be dropped into a 1 inch hole. housing option includes stainless steel. ball options include stainless, nylon, phenolic, and delrin.