Sales & Service>Required running accuracy and fit
Required running accuracy and fit

Bearing fits are also related to the required operating accuracy and easiness of mounting and dismounting. For example, to reduce resilience and vibration, clearance fits should generally not be used for bearings where high demands are placed on running accuracy. Bearings seating on the shaft and in the housing should be made to narrow dimensional tolerances, corresponding at least to grade 5 for the shaft and at least to grade 6 for the housing.

● Fits of radial bearings with solid steel shafts

Load Conditions Examples Bore Diameter (mm) Tolerance
of Shaft
Remarks
Ball bearing Tapered roller bearing
Rotating
Outer Ring
Load
Easy axial displacement of inner ring on shaft desirable Wheels on
stationary
axles
All shaft diameters g6 Use g5 and h5 where accuracy is required. In case of large bearings, f6 can be used to allow easy axial movement.
Easy axial displacement of inner ring on shaft unnecessary Tension pulleys, Rope sheaves h6
Rotating
Inner Ring
Load or
Load
Indeterminate
Light loads
(<0.06 Cr1))
Electrical appliances, Pumps, Blowers, Transport vehicles, Precision machinery, Machine tools <18 - js5 k6 and m6 can be used for single-row tapered roller bearings instead of k5 and m5.
18 to 100 < 40 js6 (j6)
100 to 200 40 to 140 k6
Normal loads
(0.06 to 0.13 Cr)
General applications, Medium and large motors, Turbines, Pumps, Engines, Gears, Woodworking machines, Vehicles, Construction equipment, Crushers <18 - js5~6 (j5-6)
18 to 100 < 40 k5 or 6
100 to 140 40 to 100 m5 or 6
140 to 200 100 to 140 m6

● Fits of radial bearings with housing

Load Conditions Examples Tolerance
for housing
bores
Remarks
Solid
Housings
Rotating outer
ring load
Normal or heavy loads Automotive wheel hubs, Vibrating screens N7 In the case of K7 or JS7(J7) is an alternative. If axial displacement of the outer ring is not required, K7 is applied.If axial displacement of outer ring is necessary, JS7 (J7) is applied
Light or variable loads Conveyor roller, Rope sheaves, Tension pulleys M7
Direction of load Indeterminate Heavy shock loads Traction motors M7
Solid or
Split
Housing
Normal or heavy loads Pumps, Medium and large motors K7
JS7(J7)
Normal or light loads
Rotating Inner
ring load
Loads of all kinds General bearing application, Railway axle boxes H7 For heavy loads, interference
fit tighter than K is used. When
high accuracy is required,
very strict tolerances should
be used for fitting.
Solid
Housing
Accurate running Desirable under normal and light loads Grinding Spindle rear ball bearings, high Speed Centrifugal Compressor free bearings JS6(J6)
Direction of load Indeterminate Grinding spindle front ball bearings, High speed centrifugal compressor fixed bearings K6
Rotating inner
ring load
Minimum noise is required Electrical home appliance H6

Notes: The above form is for steel housing, if alnico housing, the interference shall be bigger than the above.

● Tolerances for Shaft Diameters
Shaft tolerances and resultant fits

Shaft
Diameter

mm
Bearing
Broe diameter
tolerance Δdmp
g6 h6 j5 j6 js5
Over Incl. Low High High Low High Low High Low High Low High Low
  Deviations (shaft diameter)
Theoretical interference (+) / clearance (-)
Probable interference (+) / clearance (-)
1 3 -8 0 -2
+6
+4
-8
-8
-6
0
+8
+6
-6
-6
-4
+2
+10
+9
-2
-2
-1
+4
+12
+10
-2
-2
0
+2
+10
+9
-2
-2
-1
3 6 -8 0 -4
+4
+2
-12
-12
-10
0
+8
+6
-8
-8
-6
+3
+11
+10
-2
-2
-1
+6
+14
+12
-2
-2
0
+2,5
+10,5
+9
-2,5
-2,5
-1
6 10 -8 0 -5
+3
+1
-14
-14
-12
0
+8
+6
-9
-9
-7
+4
+12
+10
-2
-2
0
+7
+15
+13
-2
-2
0
+4
+11
+9
-4
-3
-1
10 18 -8 0 -6
+2
0
-17
-17
-15
0
+8
+6
-11
-11
-9
+5
+13
+11
-3
-3
-1
+8
+16
+14
-3
-3
-1
+4
+12
+10
-4
-4
-2
18 30 -10 0 -7
+3
0
-20
-20
-17
0
+10
+7
-13
-13
-10
+5
+15
+13
-4
-4
-2
+9
+19
+16
-4
-4
-4
+4,5
+14,5
+12
-4,5
-4,5
-2
30 50 -12 0 -9
+3
-1
-25
-25
-21
0
+12
+8
-16
-16
-12
+6
+18
+15
-5
-5
-2
+11
+23
+19
-5
-5
-1
+5,5
+15,5
+15
-5,5
-5,5
-3
50 80 -15 0 -10
+5
+1
-29
-29
-25
0
+15
+11
-19
-19
-15
+6
+21
+17
-7
-7
-3
+12
+27
+23
-7
-7
-3
+6,5
+21.5
+18
-6,5
-6,5
-3
80 120 -20 0 -12
+8
+2
-34
-34
-28
0
+20
+14
-22
-22
-16
+6
+26
+21
-9
-9
-4
+13
+33
+27
-9
-9
-3
+7,5
+27,5
+23
-7,5
-7,5
-3
120 180 -25 0 -14
+11
+4
-39
-39
-32
0
+25
+18
-25
-25
-18
+7
+32
+26
-11
-11
-5
+14
+39
+32
-11
-11
-4
+9
+34
+28
-9
-9
-3
Shaft
Diameter

mm
Bearing
Broe diameter
tolerance Δdmp
js6 k5 k6 m5 m6
Over Incl. Low High High Low High Low High Low High Low High Low
  Deviations (shaft diameter)
Theoretical interference (+) / clearance (-)
Probable interference (+) / clearance (-)
1 3 -8 0 +3
+11
+9
-3
-3
-1
+4
+12
+11
0
0
+1
+6
+14
+12
0
0
+2
+6
+14
+13
+2
+2
+3
+8
+16
+14
+2
+2
+4
3 6 -8 0 +4
+12
+10
-4
-4
-2
+6
+14
+13
+1
+1
+2
+9
+17
+15
+1
+1
+3
+9
+17
+16
+4
+4
+5
+12
+20
+18
+4
+4
+6
6 10 -8 0 +4,5
+12,5
+11
-4,5
-4,5
-3
+7
+15
+13
+1
+1
+3
+10
+18
+16
+1
+1
+3
+12
+20
+18
+6
+6
+8
+15
+23
+21
+6
+6
+8
10 18 -8 0 +5,5
+13,5
+11
-5,5
-5,5
-3
+9
+17
+15
+1
+1
+3
+12
+20
+18
+1
+1
+3
+15
+23
+21
+7
+7
+9
+18
+26
+24
+7
+7
+9
18 30 -10 0 +6,5
+16,5
+14
-6,5
-6,5
-4
+11
+21
+19
+2
+2
+4
+15
+25
+22
+2
+2
+5
+17
+27
+25
+8
+8
+10
+21
+31
+28
+8
+8
+11
30 50 -12 0 +8
+20
+16
-8
-8
-4
+13
+25
+22
+2
+2
+5
+18
+30
+26
+2
+2
+6
+20
+32
+29
+9
+9
+12
+25
+25
+25
+9
+9
+9
50 80 -15 0 +9,5
+24.5
+20
-9,5
-9,5
-5
+15
+25
+26
+2
+2
+6
+21
+30
+32
+2
+2
+6
+24
+32
+35
+11
+9
+15
+30
+45
+41
+11
+11
+15
80 120 -20 0 +11
+31
+25
-11
-11
-5
+18
+38
+33
+3
+3
+8
+25
+45
+39
+3
+3
+9
+28
+48
+43
+13
+13
+18
+35
+55
+49
+13
+13
+19
120 180 -25 0 +12,5
+37,5
+31
-12,5
-12,5
-6
+21
+46
+40
+3
+3
9
+28
+53
+46
+3
+3
+10
+33
+58
+52
+15
+15
+21
+40
+65
+58
+15
+15
+22

● Tolerances for Housing Bore Diameters
Housing tolerances and resultant fits

Housing
Diameter

mm
Bearing
Outside diameter
tolerance Δdmp
H6 H7 J6 J7 JS6
Over Incl. Low High High Low High Low High Low High Low High Low
  Deviations (shaft diameter)
Theoretical interference (+) / clearance (-)
Probable interference (+) / clearance (-)
6 10 0 -8 0
0
-2
+9
-17
-15
0
0
-3
+15
-23
-20
-4
+4
+2
-5
-13
-11
-7
+7
+4
+8
-16
-13
-4,5
+4,5
+3
+4,5
-12,5
-11
10 18 0 -8 0
0
-2
+11
-19
-17
0
0
-3
+18
-26
-23
-5
+5
+3
+6
-14
-12
-8
+8
+5
+10
-18
-15
-5,5
+5,5
+3
+5,5
-13.5
-11
18 30 0 -9 +0
0
-3
+13
-22
-19
0
0
-3
+21
-30
-27
-5
+5
+2
+8
-17
-14
-9
+9
+6
+12
-21
-18
-6.5
+6.5
+4
+6.5
-15.5
-13
30 50 0 -11 +0
0
-3
+16
-27
-24
0
0
-4
+25
-36
-32
-6
+6
+3
+10
-21
-18
-11
+11
+7
+14
-25
-21
-8
+8
+5
+8
-19
-16
50 80 0 -13 0
0
-4
+19
-32
-28
0
0
-5
30
-43
-38
-6
+6
+2
+13
-31
-22
-12
+12
+7
+18
-31
-26
-9.5
+9.5
+6
+9.5
-22.5
-19
80 120 0 -15 0
0
-5
+22
-37
-32
0
0
-5
+35
-50
-45
-6
+6
+1
+16
-31
-26
-13
+13
+8
+22
-37
-32
-11
+11
+6
+11
-26
-21
120 150 0 -18 0
0
-6
+25
-43
-37
0
0
-7
+40
-58
-51
-7
+7
+1
+18
-36
-30
-14
+14
+7
+26
-44
-37
-12,5
+12,5
+7
+12,5
-30,5
-25
150 180 0 -25 0
0
-7
+25
-50
-43
0
0
-8
+40
-65
-57
-7
+7
0
+18
-43
-36
-14
+14
+6
+26
-51
-43
-12,5
+12,5
+6
+12,5
-37,5
-31
180 250 0 -30 0
0
-8
+29
-59
-51
0
0
-10
+46
-76
-66
-7
+7
-1
+22
-52
-44
-16
+16
+6
+30
-60
-50
-14,5
+14,5
+6
+14,5
+14,5
-36
Housing
Diameter

mm
Bearing
Outside diameter
tolerance Δdmp
JS7 K6 K7 M7 N7
Over Incl. Low High High Low High Low High Low High Low High Low
  Deviations (shaft diameter)
Theoretical interference (+) / clearance (-)
Probable interference (+) / clearance (-)
6 10 0 -8 -7,5
+7,5
+5
+7,5
-15,5
-13
-7
+7
+5
+2
-10
-8
-10
+10
+7
+5
-13
-10
-15
+15
+12
0
-8
-5
-19
+19
+16
-4
-4
-1
10 18 0 -8 -9
+9
+6
+9
-17
-14
-9
+9
+7
+2
-10
-8
-12
+12
+9
+6
-14
-11
-18
+18
+15
0
-8
-5
-23
+23
+20
-5
-3
0
18 30 0 -9 -10.5
+10.5
+7
+10.5
-19.5
-16
-11
+11
+8
+2
-11
-8
-15
+15
+12
+6
-15
-12
-21
+21
+18
0
-9
-6
-28
+28
+25
-7
-2
+1
30 50 0 -11 -12.5
+12.5
+9
+12.5
-23.5
-20
-13
+13
+10
+3
-14
-11
-18
+18
+14
+7
-18
-14
-25
+25
+21
0
-11
-7
-33
+33
+29
-8
-3
+1
50 80 0 -13 -15
+15
+10
+15
-28
-23
-15
+15
+11
+4
-17
-13
-21
+21
+16
+9
-22
-17
-30
+30
+25
0
-13
-8
-39
+39
+34
-9
-4
+1
80 120 0 -15 -17.5
+17.5
+12
+17.5
-32.5
-27
-18
+18
+13
+4
-19
-14
-25
+25
+20
+10
-25
-20
-35
+35
+30
0
-15
-10
-45
+45
+40
-10
-5
0
120 150 0 -18 -20
+20
+13
+20
-38
-31
-21
+21
+15
+4
-22
-16
-28
+28
+21
+12
-30
-23
-40
+40
+33
0
-18
-11
-52
+52
+45
-12
-6
+1
150 180 0 -25 -20
+20
+12
+20
-45
-37
-21
+21
+14
+4
-29
-22
-28
+28
+20
+12
-37
-29
-40
+40
+32
0
-25
-17
-52
+52
+44
-12
-13
-5
180 250 0 -30 -23
+23
+13
+23
-53
-43
-24
+24
+16
+5
-35
-27
-33
+33
+23
+13
-43
-33
-46
+46
+36
0
-30
-20
-60
+60
+50
-14
-16
+6

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