Selecting a bearing
7. Tolerance and precision grade
The bearings are classified into certain precision grades. The tolerances for each grade are found in JIS and ANSI/ABMA. Minebea's products are based on JIS B 1514-1,-3, ANSI/ABMA Std.12.2 and ANSI/ABMA Std.20 The symbols used in the specification are as follows.
Symbol
Dimensions
| d | : | Nominal Bore Diameter |
| D | : | Nominal Outside Diameter |
| D1 | : | Outer ring flange outside diameter, basic |
| B | : | Nominal Inner Ring Width |
| C | : | Nominal Outer Ring Width |
| r | : | Chamfer Dimension of Inner Ring or Outer Ring |
Dimensional Differences
| Δds | : | Dimensional difference of bore diameter |
| Δdmp | : | Dimensional difference of mean bore diameter in the plane |
| (Δdm) | : | Dimensional difference of mean bore diameter |
| ΔDs | : | Dimensional difference of outside diameter |
| ΔDmp | : | Dimensional difference of mean outside diameter in the plane |
| (ΔDm) | : | Dimensional difference of mean outside diameter |
| ΔBs | : | Dimensional difference of inner ring width |
| ΔCs | : | Dimensional difference of outer ring width |
| ΔD1s | : | Deviation of a single flange outside diameter |
| ΔC1s | : | Deviation of a single width of the outer ring flange |
Limit Values of Chamfer/Radius Dimension
| rs | : | Chamfer dimension of inner ring or outer ring |
| rs min | : | Minimum dimension limit of inner ring and outer ring chamfer |
| rs max | : | Maximum dimension limit of inner ring and outer ring chamfer |
Inequality of Dimensions
| VBs | | : | Inequality of inner ring width |
| VCs | | : | Inequality of outer ring width |
| VC1s | | : | Inequality of flanged width |
Rotation Precision
| Kia (Ki) |
: | Radial runout of inner ring |
| Sia (Si) |
: | Axial runout of inner ring |
| Sd (Sdi) |
: | Side runout of inner ring
[runout of inner ring reference face with respect to the bore] |
| Kea (Ke) |
: | Radial runout of outer ring |
| Sea (Se) |
: | Axial runout of outer ring |
| SD (SD) |
: | Side runout of outer ring
[variation of outside surface generatrix inclination with respect to the outer ring reference face] |
| SD1 |
: | [variation of outside surface generatrix inclination with respect to the outer ring flange back face] |
| Seal |
: | Axial runout of outer ring flange back face |
Remark ( ) is defined by ANSI/ABMA.
Reference [ ] is the expression used in previous JIS.
Attention : Above is only for radial ball bearing.
Referred from JIS B 1514-1
Tolerance of inner ring d ≦ 18mm
(Unit : μm)
| Grade |
Dimensional difference |
Radial Runout |
Perpendicularity |
Axial runout |
Dimensional difference of width |
Inequality of width |
| Δdmp |
Δds |
Kia |
Sd |
Sia |
ΔBs |
VBs |
| Upper |
Bottom |
Upper |
Bottom |
MAX |
MAX |
MAX |
Upper |
Bottom |
MAX |
| Grade 0 |
0 |
-8 |
- |
- |
10 |
- |
- |
0 |
- 40*1
-120 |
12*1
15*2
20 |
| Grade 6 |
0 |
-7 |
- |
- |
5*1
6*2
7 |
- |
- |
0 |
- 40*1
-120 |
12*1
15*2
20 |
| Grade 5 |
0 |
-5 |
- |
- |
4 |
7 |
7 |
0 |
- 40*2
- 80 |
5 |
| Grade 4 |
0 |
-4 |
0 |
-4 |
2.5 |
3 |
3 |
0 |
- 40*2
- 80 |
2.5 |
| Grade 2 |
0 |
-2.5 |
0 |
-2.5 |
1.5 |
1.5 |
1.5 |
0 |
- 40*2
- 80 |
1.5 |
*1 the values apply only up to and including d = 2.5mm.
*2 the values apply only up to and including d = 10mm.
Tolerances of outer ring D ≦ 30mm
(Unit : μm)
| Grade |
Dimensional difference |
Radial runout |
Perpendicularity |
Axial runout |
Dimensional difference of width |
Inequality of width |
| ΔDmp |
ΔDS |
Kea |
SD |
Sea |
ΔCs |
VCs |
| Upper |
Bottom |
Upper |
Bottom |
MAX |
MAX |
MAX |
Upper |
Bottom |
MAX |
| Grade 0 |
0 |
-8*1
-9 |
- |
- |
15 |
- |
- |
0 |
- 40*2
-120 |
12*2
15*3
20 |
| Grade 6 |
0 |
-7*1
-8 |
- |
- |
8*1
9 |
- |
- |
0 |
- 40*2
-120 |
12*2
15*3
20 |
| Grade 5 |
0 |
-5*1
-6 |
- |
- |
5*1
6 |
8 |
8 |
0 |
- 40*3
- 80*4
5 |
|
| Grade 4 |
0 |
-4*1
-5 |
0 |
-4*1
-5 |
3*1
4 |
4 |
4 |
0 |
- 40*3
- 80*4
2.5 |
|
| Grade 2 |
0 |
-2.5*1
-4 |
0 |
-2.5*1
-4 |
1.5*1
2.5 |
1.5 |
1.5*1
2.5 |
0 |
- 40*3
- 80*4
1.5 |
|
*1 the values apply only up to and including D = 18mm.
*2 the values apply only up to and including d = 2.5mm.
*3 the values apply only up to and including d = 10mm.
*4 the values apply only up to and including d = 18mm.
Flange outside diameter tolerance
(Unit : μm)
| D1 |
Column 1 |
Column 2 |
| (mm) |
ΔD1s |
| Over |
Incl. |
Upper |
Bottom |
Upper |
Bottom |
|
10 |
+220 |
-36 |
0 |
-36 |
| 10 |
18 |
+270 |
-43 |
0 |
-43 |
| 18 |
30 |
+330 |
-52 |
0 |
-52 |
Remarks : When the flange outside diameter is used for location, column 2 shall apply.
Tolerances of flange width and tolerance of rotation precision related to flange
(Unit : μm)
| D |
Grade 0, 6 |
Grade 5, Grade 4, Grade 2 |
Grade 0, Grade 6 |
Grade 5 |
Grade 4 |
Grade 2 |
| (mm) |
ΔC1s |
VC1s |
| Over |
Incl. |
Upper |
Bottom |
Upper |
Bottom |
MAX |
| 2.5*1 |
30 |
0 |
-40*2 -120 |
0 |
-40*3
-80 |
12*2
15*3
20 |
5 |
2.5 |
1.5 |
(Unit : μm)
| D |
Grade 5 |
Grade 4 |
Grade 2 |
Grade 5 |
Grade 4 |
Grade 2 |
| (mm) |
SD1 |
Sea1 |
| Over |
Incl. |
MAX |
MAX |
2.5*1
18 |
18
30 |
8
8 |
4
4 |
1.5
1.5 |
11
11 |
7
7 |
3
4 |
*1 D = 2.5mm is included in this dimension division.
*2 the values apply only up to and including d = 2.5mm.
*3 the values apply only up to and including d = 10mm.
Referenced from ANSI/ABMA Std.12.2
Inner Ring tolerance d ≦ 18mm
(Unit : μm)
Grade
ABEC |
Δdmp* |
Δds |
Ki |
Sdi |
Si |
ΔBs |
VBs |
| Upper |
Bottom |
Upper |
Bottom |
MAX |
MAX |
MAX |
Upper |
Bottom |
MAX |
| 3P |
0 |
-5.1 |
+2.5 |
-7.6 |
5.1*1
7.6 |
- |
- |
0 |
-127 |
- |
| 5P |
0 |
-5.1 |
0 |
-5.1 |
3.8 |
7.6 |
7.6 |
0 |
-25.4 |
5.1 |
| 7P |
0 |
-5.1 |
0 |
-5.1 |
2.5 |
2.5 |
2.5 |
0 |
-25.4 |
2.5 |
| 9P |
0 |
-2.5 |
0 |
-2.5 |
1.3 |
1.3 |
1.3 |
0 |
-25.4 |
1.3 |
* Basically, grade 3P is provided as Δdm.
*1 the values apply only up to and including d = 10mm.
Outer Ring tolerance D ≦ 30mm
(Unit : μm)
Grade
ABEC |
ΔDmp* |
ΔDs |
Ke |
SD |
Se |
ΔCs |
VCs |
| Open |
shield/seal |
| Upper |
Bottom |
Upper |
Bottom |
Upper |
Bottom |
MAX |
MAX |
MAX |
Upper |
Bottom |
MAX |
| 3P |
0 |
-7.6 |
+2.5 |
-10.2 |
+5.1 |
-12.7 |
10.2 |
- |
- |
0 |
-127 |
- |
| 5P |
0 |
-5.1 |
0 |
-5.1 |
+1 |
-6.1 |
5.1 |
7.6 |
7.6 |
0 |
-25.4 |
5.1 |
| 7P |
0 |
-5.1 |
0 |
-5.1 |
+1 |
-6.1 |
3.8 |
3.8 |
5.1 |
0 |
-25.4 |
2.5 |
| 9P |
0 |
-2.5*1
-3.8 |
0 |
-2.5*1
-3.8 |
- |
- |
1.3*1
2.5 |
1.3 |
1.3*1
2.5 |
0 |
-25.4 |
1.3 |
* Basically, grade 3P is provided as ΔDm.
*1 the values apply only up to and including D = 18mm.
Referred from ANSI/ABMA Std.20
Inner Ring tolerance d ≦ 18mm
(Unit : μm)
Grade
ABEC |
Δdmp |
Kia |
Sia |
ΔBs |
VBs |
| Upper |
Bottom |
MAX |
MAX |
Upper |
Bottom |
MAX |
| 1 |
0 |
-8 |
10 |
15*1
20 |
0
0 |
- 40*1
-120 |
12*1
15*2
20 |
*1 the values apply only over and including d = 0.6mm or up to and including d = 10mm.
*2 the values apply only up to and including d = 10mm.
Outer Ring tolerance D ≦ 30mm
(Unit : μm)
Grade
ABEC |
ΔDmp |
Kea |
Sea |
ΔCs |
VCs |
| Upper |
Bottom |
MAX |
MAX |
Upper |
Bottom |
MAX |
| 1 |
0 |
-8*1
-9 |
15 |
15*2
20*1
25 |
0 |
- 40*3
-120 |
12*3
15*4
20 |
*1 the values apply only up to and including D = 18mm.
*2 the values apply only up to and including D = 6mm.
*3 the values apply only up to and including d = 2.5mm.
*4 the values apply only up to and including d = 10mm.
Referenced from JIS B 1514-3
Maximum values of chamfer dimension for radial bearings
(Unit : mm)
| rs min |
d |
rs max |
| Over |
Incl. |
Radial direction |
Axial direction |
0.05
0.08
0.1
0.15
0.2 |
-
-
-
-
- |
-
-
-
-
- |
0.1
0.16
0.2
0.3
0.5 |
0.2
0.3
0.4
0.6
0.8 |
| 0.3 |
-
40 |
40
- |
0.6
0.8 |
1
1 |
| 0.6 |
-
40 |
40
- |
1
1.3 |
2
2 |
| 1 |
-
50 |
50
- |
1.5
1.9 |
3
3 |
|
