|
Selection of grain sizes for diamond and CBN
The size of the abrasive grain influences the stock removal rate and the attainable surface and cutting quality considerably, and is one of the factors which determnes the life of the grinding tool.
| Coarse abrasive grain |
= higher stock removal rate |
 |
= prolonged tool life |
| Finer abrasive grain |
= improved grinding quality* |
|
= lower stock removal rate |
| = shorter tool life |
*)
This primarily applies to the use of diamond grains. In the case of CBN, the grain size has less influence on the quality of the workpiece surface finish and as coarse a grain as possible should therefore be used.
The abrasive grain size should therefore be selected according to the following rule of thumb:
|
The abrasive grain should be as coarse as possible and as fine as absolutely necessary!
|
Table
|
International standard of grain sizes for diamond and CBN
|
|
Sieve grain designations
|
Fine grain sizes
|
Diamond
Riegger standard
FEPA standard
|
CBN
Riegger standard
FEPA standard
|
Nom. mesh width
acc. to ISO
6106 DIN 848
Part 1
|
Diamond
Riegger standard |
Grain size |
CBN
Riegger standard |
|
Close
|
Wide
|
Close
|
Wide
|
µm
|
|
in µm
|
|
|
D 1181
|
D 1182
|
B 1181
|
B 1182
|
1180/1000
|
D 30
|
30-60
|
B 30
|
|
D 1001
|
B 1001
|
1000/850
|
D 25
|
30-40
|
|
|
D 851
|
D 852
|
B 851
|
B 852
|
850/710
|
D 20
|
20-30
|
|
|
D 711
|
B711
|
710//600
|
D 15
|
12-25
|
B 15
|
|
D 601
|
D 602
|
B 601
|
B 602
|
600/ 500
|
D 15.1
|
15-20
|
|
|
D 501
|
B 501
|
500/425
|
D 12
|
8-15
|
|
|
D 426
|
D 427
|
B 426
|
B 427
|
425/355
|
D 12.1
|
8-12
|
|
|
D 356
|
B 356
|
355/300
|
D 9
|
6-12
|
B 9
|
|
D 301
|
|
B 301
|
|
300//250
|
D 7
|
5-10
|
B 7
|
|
D 251
|
D 252
|
B 251
|
B252
|
250/212
|
D 3
|
2-5
|
B 3
|
|
D 213
|
B 213
|
212/180
|
D 1
|
1-3
|
B 1
|
|
D 181
|
|
B 181
|
|
180/150
|
D 0,7
|
0-1
|
|
|
D 151
|
|
B 151
|
|
150/125
|
D 0,25
|
0-0,5
|
|
D 126
|
|
B 126
|
|
125/106
|
FEPA standard
|
|
|
D 107
|
|
B 107
|
|
106/90
|
M 1.0
|
0,5-1,5
|
|
D 91
|
|
B 91
|
|
90/75
|
M 1.6
|
1,0-2,5
|
|
D 76
|
|
B 76
|
|
75/63
|
M 2.5
|
1,6-3,5
|
|
D 64
|
|
B 64
|
|
63/53
|
M 4.0
|
2,5-5,5
|
|
D 54
|
|
B 54
|
|
53/45
|
M 6.3
|
4-9
|
|
D 46
|
|
B 46
|
|
45/38
|
M 10.0
|
6-14
|
| |
M 16.0
|
10-22
|
|
M 25.0
|
16-34
|
|
M 40.0
|
27-53
|
|
M 63
|
42-84
|
|
|
