Technical Information
1. BEARING MATERIALS:
The standard material for FKG bearing rings and balls is vacuum-processed high carbon chromioum steel allowing high quality consitency and long bearing service life. Material symbol is GCr15.
CHEMICAL COMPOSITION OF BEARING STEEL
|
Steel No. |
Symbol |
Chemical Composition (Wt%) |
|
Gcr15 |
AISI 52100 |
C
0.95-1.05 |
Cr
1.30-1.65 |
Si
0.15-0.35 |
Mn
0.2-0.4 |
P
<0.027 |
S
<0.02 |
THE COMPARISON TABLE FOR EACH STANDARD
|
China |
ISO |
USA |
Japan |
Germany |
France |
Sweden |
|
GB |
|
AISI |
JIS |
DIN |
NF |
|
|
Gcr15 |
683/xv11 |
52100 |
SUJ2 |
100Cr6 |
100C6 |
SKF3 | CAGES
In general, FKG cages are pressed steel ribbon cages & pressed steel snap cages. For wheel hub bearings and A/C beairngs, the cages are made from Nylon 66 with glass fiber.
SHIELDS & SEALS
The standard seals are made of oil and wear-resistant nitrile rubber(NBR) with a sheet steel reinforcement. SPCC is the standard material for shields we apply.
LUBRICATION
The grease can be applied upon customer's requirements. In general, Alvania R 2 is used for FKG small ball bearing. RONEX MP from ESSO Co. and ALVANIA R3 from SHELL are used for wheel hub bearings.
Details as per our grease conversion table
2. BEARING TOLERANCE & ACCURACY
Bearing accuracy consists of dimensional accuracy and running accuracy. The normal grade is P0,a higher grade is P6 and P2 is the highest grade.
Accuracy Grade Standard Conversion Table
|
Country |
Standard |
Tolerance Grade |
|
China |
GB |
0 |
6 |
5 |
4 |
|
American |
ANSI |
ABEC-1 |
ABEC-3 |
ABEC-5 |
ABEC-7 |
|
|
ISO |
0 |
6 |
5 |
4 |
|
Germany |
DIN |
P0 |
P6 |
P5 |
P4 |
|
Japan |
JIS |
P0 |
P6 |
P5 |
P4 |
3. INTERNAL CLEARANCE
The radial internal clearance of a bearing is of considerable importance, if satisfactory operation is to be obtained, as it greatly influences beairng performance including fatige life, vibration, noise, heat generation, etc.
The radial clearances of FKG bearings can be classified into C2, Standard, C3, C4 & C5
RADIAL CLEARANCE TABLE (μm)
|
Bore Diameter |
C2 |
Standard |
C3 |
C4 |
C5 |
|
over |
incl |
min |
max |
min |
max |
min |
max |
min |
max |
min |
max |
|
10 |
18 |
0 |
9 |
3 |
18 |
11 |
25 |
18 |
33 |
25 |
45 |
|
18 |
24 |
0 |
10 |
5 |
20 |
13 |
28 |
20 |
36 |
28 |
48 |
|
24 |
30 |
1 |
11 |
5 |
20 |
13 |
28 |
23 |
41 |
30 |
53 |
|
30 |
40 |
1 |
11 |
6 |
20 |
15 |
33 |
28 |
46 |
40 |
64 |
|
40 |
50 |
1 |
11 |
6 |
23 |
18 |
36 |
30 |
51 |
46 |
76 | NOTE
1. Standard clearance is C0.
2. C2 Group clearance only for bearings over ABEC-3 accurancy.
4. VIBRATION AND NOISE
The vibration and noise of bearings are classified in four classes Z1, Z2, Z3, and Z4. It is measured by the instrument of S0910-1. For special requirement, it is measured by BVT-1 and classified as V1, V2, V3 , and V4.
The data are shown in the following tables, different vibration and noise requirement should be mentioned in order.
MAXIMUM VIBRATION ACCELERATION OF SINGLE BEARING(Tolerance in dB)
 |
