Mounting of Self-Aligning Ball Bearings on Adapter Sleeve

When installing self-aligning ball bearings into a housing, it is often impossible to measure the radial clearance directly. To simplify the procedure, the mounting process can be carried out in two stages without extensive measuring.

Step 1: Initial Tightening

The adapter sleeve nut is first tightened with a torque that expands the inner ring of the bearing by about 10% of the average initial radial clearance. The required torque in Nm​ can be determined from this table:

For this operation, an adjustable hook spanner can be used together with a torque wrench. We sell these in our Webshop, search for “adjustable hook spanner”. Or use this link:

Basket Basket Order Adjustable Hook Spanners

When using a torque wrench extension, you need to reduce the set torque on your wrench. Consult your user manual, or use this calculation:

You can find the S dimension in our datasheet or directly printed on the tool. Use this formula to calculate the torque setting:

M1 = M2 * L1 / (L1 + S)

M1 = torque setting of the wrench

M2 = actual torque applied to the nut

L1 = the normal length of the wrench

S = extension length

Example:

You need to fasten the nut with 48 Nm, you are using a 500 mm wrench and a 150 mm extension.

M1 = 48 * 500 / (500 + 150)

M1 = 37

You need to set your torque wrench to 37 Nm, to end up with 48 Nm at the nut via the extension.

Step 2: Angular Tightening

After the initial torque has been applied, the nut is then further tightened by turning it a specific angle according to this table:

Bore reference numberAngle of rotation in degrees °
12.. K.C322.. K.C313.. K.C323.. K.C3
0550485651
0650485650
0762606863
0862606862
0968687672
1068687671
1164647166
1264647166
1364647166
1478788480
1578788480
1678788480
179896106100
189896106100
199896106100
209896104100
21118118126122
22118118126122

Example:

  • Bearing type: Self-aligning ball bearing 1309K.C3 with adapter sleeve H 309
  • Step 1: Tightening torque = 48 Nm
  • Step 2: Additional angle = 76°

Important note

To reduce the influence of different friction levels between the adapter sleeve outside diameter and the bearing bore during clearance reduction, both surfaces must be cleaned and dried before assembly. Any protective oil or anti-corrosion coating must be removed.