The cast housings of the units for extreme temperatures are interchangeable with those of the standard SKFY-bearing units except for a few sizeswhich have some dimensions whichdiffer slightly. The principle differencesapart from this are● the surfaces are coated with zincand yellow chromate; this galvanised layer provides added protectionagainst corrosion and gives thehousings a distinctive appearance;● the housing bore is coated with alubricating paste and the tolerancesare such that misalignment compensation can be achieved at alltimes and at all temperatures;● there is no grease nipple for obviousreasons – the bearings are lubricatedfor life.