Schaeffler Group Greater China
CONTACT
Application Engineering Department Industrial
Tel. +86 21 39576000
Fax +86 21 39593210
Frequently Asked Questions About Bearings
Etching surface
Question:
Why does visible dull-grey colour on the bearing surface (inner ring or outer ring) sometimes, instead of normal finished coulour?
Etched ring
Not etched ring
Answer:
- Etching is carried out as one method of random quality inspections during manufacturing process, grinding burn defect due to high temperature can be detected, therefor it ensure better quality with high reliability.
- The colour of bearing ring after etched is shallow gray or dull gray.
- Compare to the etched and non etched bearing, there is no difference regarding dimension deviation, geometric tolerance and function. On the contrary, etching process can guarantee product with high quality and reliability. So etched product can be used saftely.
Normally, an instruction sheet is attached in the package for this kind of bearing
