30 reasons for SKF bearing rings:

1. Oil has impurities;

2. Insufficient lubrication (the oil level is too low, and improper storage causes oil or grease to leak through the seal);

3. SKF bearing's  http://www.alierbearings.com/brand/skf/index3.html  clearance is too small or too large (selection problem)

4. The impurities such as sand or carbon particles are mixed into the bearing to act as abrasive.

5. The water in the bearing is mixed with water, acid or paint and so on.

6. The bearing is compressed by the seat hole (the roundness of the hole is not good, or the seat hole is distorted);

7. The underside of the bearing pedestal is uneven (leading to the deformation of the seat hole and even cracks in the bearing seat);

8. There are sundries in the bearing hole (residual chips, dust particles, etc.);

9. Eccentricity of sealing ring (touching adjacent parts and causing friction);

10. The bearing is subjected to additional loads (the bearing is either in a tight axial position or on a shaft with two fixed end bearings);

11. The bearing is too loose with the shaft (the diameter of the shaft is small or tight);

12. The SKF bearing has too small clearance and too tight rotation (the tight sleeve is too tight);

13. The bearing has noise (the end face of the roller is caused by the sliding of the ball);

14. The thermal elongation of the shaft is too large (the bearing is subjected to the static axial loading);

15. The shaft shoulder is too large (contact the seal of the bearing and friction);

16. The shoulder of the seat hole is too large (the sealing part of the bearing is distorted);

17. The clearance of labyrinth seals is too small (friction with the shaft);

18. The teeth of the locking washer are bent (touching the bearing and causing friction);

19. Improper positioning of the oil swing ring (touching flange cover and friction);

20. There is a pressure pit on the ball or roller (which is caused by striking the bearing with a hammer when mounting);

21. Bearing noise (with external vibration source interference);

22. The bearing is subjected to thermal discoloration and deformation (caused by the use of a spray gun to heat and remove the bearing);

23. The shaft is too thick to make the actual match too tight (resulting in excessive bearing temperature or noise);

24. The diameter of the seat hole is small (the bearing temperature is too high);

25. The diameter of bearing seat hole is too large, the actual match is too loose (the bearing temperature is too high -- the outer ring is slippery);

26. The hole of the bearing seat is enlarged (the bearing hole of the non-ferrous metal is enlarged or enlarged due to thermal expansion);

27.

28. Bearing raceway rusts;

29. Steel ball, raceway wear (grinding is not qualified or the product has bruising);

30. Failure of the ring raceway (manufacturer's problem)