The SKF HA311 adapter sleeve is a genuine SKF component engineered for the precise and secure mounting of bearings with a tapered bore onto either smooth or stepped cylindrical shafts. This essential accessory simplifies bearing installation, eliminating the need for additional shaft location mechanisms. It features a 50mm bore diameter, a 55mm shaft diameter, and a width of 40mm. The HA311 is commonly paired with an SKF KM11 lock nut and an MB11 locking washer to ensure robust fastening and reliable operation in various industrial and agricultural applications.