Fits for needle roller bearings with an inner ring

The main dimensions of needle roller bearings with an inner ring have tight tolerances. In order to achieve a good bearing seat while at the same time being easy to assemble, the outside diameter of the shafts or the inside diameter of the bores are tolerated according to the fit system. The recommended shaft and bore fits are given below.

Recommended fit for the shaft

Load Shaft diameter Dimensional tolerance
Low and variable loads
(P ≤ 0,05 C)		 Dw ≤ 10 mm k5
10 < Dw ≤ 25 mm k6
25 < Dw ≤ 100 mm m6
Normal to high loads
(0,05 C < P ≤ 0,1 C)		 Dw ≤ 25 mm k5
25 < Dw ≤ 60 mm m6
60 < Dw ≤ 100 mm n6
100 < Dw ≤ 400 mm p6
High to very high loads
(P > 0,1 C)		 50 < Dw ≤ 100 mm n6
100 < Dw ≤ 200 mm p6
Dw > 200 mm r6
C = basic dynamic load rating | P = equivalent dynamic bearing load
Dimensional tolerance limits

Recommended fit for the bore

Load Limitation Dimensional tolerance
Point load on the outer ring, e.g.:
Umfangslast am Außenring Umfangslast am Außenring
Heat supply through the shaft none G7
Light to normal loads (P ≤ 0,1 C) none H8
High loads (P > 0,1 C) none H7
Indefinite load direction Light to normal loads (P ≤ 0,05 C) none J7
Normal to high loads (P > 0,05 C) Only for unsplit housings K7
High impact loads Only for unsplit housings M7
Circumferential load on the outer ring, e.g.:
Umfangslast am Außenring Umfangslast am Außenring Umfangslast am Außenring
Small and variable Loads (P ≤ 0,05 C) Only for unsplit housings M7
Normal to high loads (0,05 C < P ≤ 0,1 C) Only for unsplit housings N7
Very high loads (P > 0,1 C) Only for unsplit housings P7
C = basic dynamic load rating | P = equivalent dynamic bearing load
Dimensional tolerance limits

This information is to be seen as a recommendation. The data has been carefully compiled from various sources, but no guarantee is given for any information.