Rolling ball bearings have classes, and JIS and ABMA specify tolerances and tolerance values for each class. MinebeaMitsumi's products are based on JIS B 1514-1, -3, ABMA 12.2 and 20.
The main symbols used in the specification are as follows.
Tolerance and tolerance value
- ■Dimensions
- d :Nominal bore diameter
- D :Nominal outer diameter
- D1 :Nominal outer ring flange outer diameter
- B :Nominal Inner Ring Width
- C :Nominal Outer Ring Width
- r :Nominal chamfer dimensions of inner ring or outer ring
- ■Dimensional Differences
- Δds :Dimensional difference of actual bore diameter
- Δdmp:Dimensional difference of average bore diameter in the plane
- (Δdm):Dimensional difference of average bore diameter
- ΔDs :Dimensional difference of actual outer diameter
- ΔDmp:Dimensional difference of average outer diameter in the plane
- (ΔDm):Dimensional difference of average outer diameter
- ΔBs :Dimensional difference of actual inner ring width
- ΔCs :Dimensional difference of actual outer ring width
- ΔD1s :Dimensional difference of actual outer ring flange outer diameter
- ΔC1s :Dimensional difference of actual outer ring flange width
- ■Chamfer
- rs :Actual chamfer dimensions of inner ring and outer ring
- rs min:Minimum value of rs
- rs max:Maximum value of rs
- ■Inequality of Dimensions
- VBs :Inequality of inner ring width
- VCs :Inequality of outer ring width
- VC1s:Inequality of flanged outer ring width
- ■Rotation Precision
- Kia(Ki) :Radial runout of inner ring
- Sia(Si) :Axial runout of inner ring
- Sd(Sdi):Perpendicularity of inner ring side surface with respect to the inner diameter axis
- Kea(Ke):Radial runout of outer ring
- Sea(Se):Axial runout of outer ring
- SD(SD):Perpendicularity of outer ring outer diameter surface with respect to the side surface
- SD1 :Perpendicularity of outer ring outer diameter surface to flange back
- Seal :Axial runout of outer ring flange back surface
- Remark ( ) is defined by ABMA.
- Above is only for radial ball bearing.
Excerpt from JIS B 1514-1
Inner ring tolerance and tolerance valued≦18 mm
(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 Applicable to those with inner diameter of 2.5 mm or less.
*2 Applicable to those with inner diameter of 10mm or less.
Outer ring tolerance and tolerance value D≦30 mm
(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 Applicable to those with outer diameter of 18 mm or less.
*2 Applicable to those with inner diameter of 2.5 mm or less.
*3 Applicable to those with inner diameter of 10 mm or less.
*4 Applicable to those with inner diameter of 18 mm or less.
Tolerance of outer ring flange outer diameter
(Unit : μm)
| D1 | Non-positioning flange | ||
|---|---|---|---|
| (mm) | ΔD1s | ||
| Over | Incl. | Upper | Bottom |
| 10 | +220 | -36 | |
| 10 | 18 | +270 | -43 |
| 18 | 30 | +330 | -52 |
Remarks : Contact us when using the flange outer diameter surface for positioning.
Tolerance and tolerance value of flange width and tolerance value of flange-related rotation precision
(Unit : μm)
| D | Grade 0, Grade 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 Outer diameter 2.5 mm is included in this dimension division.
*2 Applicable to those with inner diameter of 2.5 mm or less.
*3 Applicable to those with inner diameter of 10mm or less.
Excerpt from ABMA 20
Inner ring tolerance and tolerance value d≦18 mm
(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 Applicable to those with inner diameter of 0.6 mm or more, 2.5 mm or less.
*2 Applicable to those with inner diameter of 10 mm or less.
Outer ring tolerance and tolerance value D≦130 mm
(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 Applicable to those with outer diameter of 18 mm or less.
*2 Applicable to those with outer diameter of 6mm or less.
*3 Applicable to those with inner diameter of 2.5 mm or less.
*4 Applicable to those with inner diameter of 10mm or less.
Excerpt from ABMA 12.2
Inner ring tolerance and tolerance value d≦18 mm
(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 |
Note 1: Grade 3P is usually defined by Δdm.
*1 Applicable to those with inner diameter of 10 mm or less.
Outer ring tolerance and tolerance value D≦30 mm
(Unit : μm)
| Grade ABEC |
ΔDmp* | ΔDs | Ke | Cs | 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 |
Note 2: Grade 3P is usually specified by ΔDm.
*1 Applicable to those with outer diameter of 18 mm or less.
Excerpt from JIS B 1514-3
Allowable limit value of chamfer dimension for radial ball 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 |
*1 The value in the radial direction applies to those with width of 2 mm or less.
