MinebeaMitsumi Product Site

  1. HOME
  2. Engineering Information
  3. Bearings
  4. Tolerance and precision grade
  1. Engineering Information
  2. Bearings
  3. Miniature & small ball bearings

Tolerance and precision grade

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)
: Radial 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		 ΔdmpNote 1 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		 ΔDmpNote 2 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
  • 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*1
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.

Related page

Miniature & small ball bearings

Engineering Information for Miniature & small ball bearings

Selecting the Right Part

Miniature & small ball bearing Product Catalog

Technical Data

Bearing Types
Names and Symbols
Part Numbering System
Selecting Process
Application Structure, Required Performance, Environment
Material
Shield and Seal
Retainer
Load rating and rating life
Tolerance and precision grade
Measurement methods
Internal Clearance
Fits
Designs of shaft and housing
Preload
Displacement
Torque
Vibration by forced rotation
Noise
Combination with Resin Parts
Lubricants
Handling of a Bearing
Trouble Symptoms, Causes and Countermeasures
New Technology Information

Click here for technical questions, requests for various materials, etc.

Contact

Contact Us

Please click the inquiry type below according to your question. Each product / sales representative will respond to you.