certific at e - NOC international

108 KRW
Extended modified service life
Degree of contamination Coefficient e C
D pw ≥ 100 mm
Meticulous cleanliness
Particle size equivalent to the lubrication film thickness,
determined in lab environment 1
Good cleanliness, superfine filtration of the oil
supplied, sealed. greased bearings 0.9 - 0.8
Standard cleanliness, fine filtration of the oil
supplied, greased bearings with covers 0.8 - 0.6
Slight contamination,
Slight contamination in oil supply 0.6 - 0.4
Typical contamination, bearings contaminated
with abraded particles of other machine elements 0.4 - 0.2
High contamination
Heavily contaminated bearings,
insufficiently sealed 0.1 - 0
Very high contamination 0
Heavy contamination, i.e. with e C ≈0 may result in a substantial reduction of the nominal service life.
The factor a DIN , calculated according to DIN ISO 281, annex 1, depends on the contamination factor e C , the fatigue
limit stress factor C U , the dynamic equivalent load P, and the viscosity ratio κ. The follwing equation applies:
e eC
· CU aDIN = f –——— , κ
P
The mathematical relations for radial and axial ball bearings are listed in the annex of DIN ISO 281. The following
4 diagrams may be useful in practice.