Bearing Specifications

I. MATERIALS

RINGS & BALLS--- Bearing Experts uses SAE 52100 vacuum degassed, high carbon, chromium

bearing steel as its standard material for precision bearing rings and balls. In applications where a

corrosive environment may be present, we recommend the use of AISI 440 C martensitic stainless

steel. Table 1 below shows the chemical compositions of chromium bearing steel:

TABLE 1

 

Country

 

Standard

 

Symbol

Chemical compositions (%)

C

Si

Mn

P

S

Cr

Mo

USA / INDIA

ASTMA295

52100

0.98-1.10

0.15-0.35

0.25-0.45

≤ 0.025 

≤ 0.025

1.30-1.60

≤ 0.10

China

GB/T18254

GCr15

0.95-1.05

0.15-0.35

0.25-0.45

≤ 0.025

≤ 0.025

1.40-1.65

≤ 0.10

Japan

JISG4805

SUJ2

0.95-1.10

0.15-0.35

  ≤ 0.50

≤ 0.025

≤ 0.025

1.30-1.60

≤ 0.08

GERMANY

DIN

100Cr6

0.95-1.05

0.15-0.35

0.25-0.45

≤ 0.025

≤ 0.025

1.40-1.65

≤ 0.10

SWEDEN

D33

SKF3

0.95-1.10

0.15-0.35

0.25-0.45

≤ 0.025

≤ 0.015

1.35-1.65

≤ 0.10

KOREA

KSD3525

STB2

0.95-1.10

0.15-0.35

≤ 0.50

≤ 0.025

≤ 0.025

1.30-1.60

≤ 0.08

 

    RETAINERS--- Bearing Experts standard bearing retainers are made from cold rolled carbon steel.

However, in case of corrosive environment, misalignment, or high speed operation, stainless steel, nylons,

or phenolic resins can be used upon request.

SEALS & SHIELDS--- Bearing Experts shields also employ carbon steel as standard, and the option of AISI300

stainless steel is available when needed. Bearing Experts uses a variety of sealing materials to meet the

requirements of high temperature operation and compatibility with greases. Nitrile rubber is the

standard material used, while fluorocarbon, silicon, and Teflon seals are commonly specified for

high temperature running.

LUBRICANTS--- Bearing Experts standard greases are listed below in TABLE 2 and are supplied with

shield or sealed bearings as standard. Many different types of oil lubricants can also be supplied upon

request, and are supplied as standard for open bearings.

TABLE 2

 

Manufacturers

 

Lubricants

Operating temperature

 

USA specification

C

F

GREASES

SHELL

ALVANIA  RS#2

-25 / +120

-13 / +248

 

EXXON(ESSO)

BEACON 325

-55 / +120

-67 / +248

MIL-G-3278A

 

ANDOK C

-25 / +120

-13 / +248

 

 

ANDOK B

-30 / +110

-22 / +230

MIL-G-18709A

MOBIL

GREASE 28

-60 / +175

-76 / +347

MIL-G-81322A

CHEVRON

CHEVRON SRI#2

-30 / +175

-22 / +347

 

DOW CORNING

DC 33

-70 / +180

-94 / +356

MIL-G-46886

DUPONT

KRYTOX 240AB

-40 / +227

-40 / +440

MIL-G-38220

KYODO YUSHI

MULTEMP SRL

-40 / +150

-40 / +302

 

KYODO YUSHI

MULTEMP PS2

-54 / +130

-65 / +266

 

CHINA

HANGU GREASE

-20 / + 120

-04 / +248

 

II.  BEARING ACCURACY

The bearing accuracy includes dimensional accuracy and running accuracy, which has corresponding domestic and international standard, but the domestic standards of all countries accord with the international standard. TABLE 3 shows the radial ball bearing accuracy grade.

TABLE 3

COUNTRY

STANDARD

                   ACCURACY GRADE

USA

ANSI/AFBMA STD.20

ABEC-1

ABEC-3

ABEC-5

ABEC-7

ABEC-9

INTERNATIONAL

ISO 492

CLASS 0

CLASS 6

CLASS 5

CLASS 4

CLASS 2

CHINA

GB/T307.1

PO

P6

P5

P4

P2

JAPAN

JIS B 1514

0

6

5

4

2

GERMANY

DIN 620

P0

P6

P5

P4

P2

III.  BEARING INTERNAL TOLERANCE

The internal clearance of bearings refers to the value of displacement of the unfixed ring when it moves against the fixed ring in radial or axial direction, it can be classified into radial clearance and axial clearance. Generally, the radial clearance is controlled for deep groove ball bearings, while the axial clearance is controlled for double row angular contact ball bearings. TABLE 4 shows the clearance for radial deep groove ball bearings.

TABLE 4

Bore (d)

C2

C0

C3

C4

C5

> 

min

max

min

max

min

max

min

max

min

max

2.5

10

0

7

2

13

8

23

14

29

20

37

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

45

73

50

65

1

15

8

28

23

43

38

61

55

90

65

80

1

15

10

30

25

51

46

71

65

105

80

100

1

18

12

36

30

58

53

84

75

120

IV.  BEARING PACKAGING

Bearing Experts bearings have been cleaned, rust-prevented and packaged before delivery to

customers. Under normal storage conditions, the bearings will not get rusted within one year after delivery.

Bearing Experts bearing packaging consists of interior package and outer package. Interior package is oilpaper or plastic tube, outer package is carton lined with plastic sheet. The package for ocean transportation is wooden pallet or iron pallet wrapped with plastic sheet and packed with metal strips. Individual box packaging or other modes are also available upon request.

v.           WARRANTY

Bearing Experts bearings are warranted to be free from defects in materials and workmanship. The obligation of Bearing Experts under this warranty is limited to replacing any bearing which is proven to be defective within 180 days from date of purchase, under the following provisions.

1. The application of the product was approved by Bearing Experts.

2. Analysis by Bearing Experts verified that the product was properly handled, mounted,

3. Lubricated and not subjected to abuse.