When the Vacuum Cleaner Hospital was open and operating here-Bill the owner-operator serviced the Sanitaire vacuums used by ECU here.Since the plastic fans--and fancases were wearing out from the sandy dirt tracked in--they insisted on metal fans--he was able to get some--beleive it was the same fan that Koblentz uses-they are not steel but an aluminun alloy-same as Royal uses.And Bill was able to get steel fancase liners for the Sanitiares-these were good if the orig fancase was badly worn or cracked.You cement the steel one in place-and away you go!Can't remember the supplier he got the fans and fancases from.Would be helpful to Sanitiare users that use their machines a lot esp under tough conditions that quickly wear out or break the plastic fans and fancases.The sandy dirt here is tough on the plastic Kirby fans,too-lots get replaced here from erosion.-Yes,even new Sentria fans.