Shaft and housing tolerances

SKF recommends machining the shaft seat for needle roller / cylindrical roller thrust bearings to a k5 tolerance class for bearings with or without an inner ring.
For the housing bore seat, SKF recommends a K6 tolerance class. For stiff bearing arrangements, SKF recommends a M6 housing bore tolerance class.
In addition to their interference fit on the shaft and in the housing, the bearing rings must be axially located by a shaft shoulder or locating ring.