|
Radial clearance is the movement of the inner ring in relation to the outer ring. This movement
can be effected by shaft and housing fitting tolernaces and working temperature. Selecting the correct radial clearance
will depend up your fitting requirements and temperatures. Many roller and ball bearing types can be
purchased with the following clearance specifications. These specifications are virtually universal across all
bearing manufacturers although some manufacturers such as NSK go further and provide subgroup
tolernace bands that fit between the four basic clearance types.
|
Code |
Description |
|
C2 |
Radial
clearance lower than CN
|
|
CN |
Normal
radial clearance
|
|
C3 |
Radial
clearance higher than CN
|
|
C4 |
Radial
clearance higher than C3
|
So what do these tolerances mean in terms of physical movement? Depending on the the bearings
size, the actual clearance values can be read from the following table (values in microns).
|
Bore size (mm) |
Radial
bearing clearance (microns) |
|
d |
C2 |
CN |
C3 |
C4 |
|
More than |
Up to |
Min. |
Max. |
Min. |
Max. |
Min. |
Max. |
Min. |
Max. |
|
-
24 |
24
30 |
0
0 |
25
25 |
20
20 |
45
45 |
35
35 |
60
60 |
50
50 |
75
75 |
|
30
40
50 |
40
50
65 |
5
5
10 |
30
35
40 |
25
30
40 |
50
60
70 |
45
50
60 |
70
80
90 |
60
70
80 |
85
100
110 |
|
65
80
100 |
80
100
120 |
10
15
15 |
45
50
55 |
40
50
50 |
75
85
90 |
65
75
85 |
100
110
125 |
90
105
125 |
125
140
165 |
|
120
140
160 |
140
160
180 |
15
20
25 |
60
70
75 |
60
70
75 |
105
120
125 |
100
115
120 |
145
165
170 |
145
165
170 |
190
215
220 |
|
180
200
225 |
200
225
250 |
35
45
45 |
90
105
110 |
90
105
110 |
145
165
175 |
140
160
170 |
195
220
235 |
195
220
235 |
250
280
300 |
|
250
280
315 |
280
315
355 |
55
55
65 |
125
130
145 |
125
130
145 |
195
205
225 |
190
200
225 |
260
275
305 |
260
275
305 |
330
350
385 |
|
355
400
450 |
400
450
500 |
100
110
110 |
190
210
220 |
190
210
220 |
280
310
330 |
280
310
330 |
370
410
440 |
370
410
440 |
460
510
550 |
|
