Abrasive Reference Chart for Coated Abrasive, Diamond and Cubic Boron Nitride

Abrasive Reference Overview - Two primary standards exist for classifying the grit size of abrasives. In the U.S., the CAMI (Coated Abrasives Manufacturing Institute) standard is used; Europe uses the FEPA (Federation of European Producers of Abrasives) standard. Japan uses the JIS (Japanese Industrial Standard), which is equivalent to the FEPA standard. FEPA graded abrasives can be easily distinguished by the letter "P" in front of the grit number, such as P240.

There are sizing differences between the CAMI and FEPA standards, so the two standards are not universal. The following chart compares the CAMI and FEPA "P" abrasive designations with the average grit size in micrometres (µm).


FEPA Grit Designation for Coated Abrasives CAMI Grit Designation Average Grain Diameter in Micrometers(µm)
MACROGRITS – Abrasive grains coarser than 240 grit
Extra Coarse
P12
1815
P16
1324
P20
1000
P24
764
24
708
P30
642
30
632
36
530
P36
538
Coarse
P40
40
425
50
348
P50
336
Medium
60
265
P60
269
P80
201
80
190
Fine
P100
162
100
140
P120
125
120
115
Very Fine
P150
100
150
92
P180
180
82
P220
220
68
MICROGRITS – abrasive grains 240 grit and finer
Very Fine
P240
58.5 (+/- 2)
240
53
P280
52.2 (+/- 2)
P320
46.2 (+/- 1.5)
P360
40.5 (+/- 1.5)
Extra Fine
320
36
P400
35 (+/- 1.5)
P500
30.2 (+/- 1.5)
360
28
P600
25.8 (+/- 1)
Super Fine
400
23
P800
21.8 (+/- 1)
500
20
P1000
18.3 (+/- 1)
600
16
P1200
15.3 (+/- 1)
Ultra Fine
P1500
800
12.6 (+/- 1)
P2000
1000
10.3 (+/- 0.8)
P2500
8.4 (+/- 0.5)




Abrasive Reference - Diamond and Cubic Boron Nitride

The following chart compares the FEPA, U.S. Standard and British Standard grit size designations for Diamond and Cubic Boron Nitride (cBN). Diamond grits are prefixed with a "D" and CBN with a "B".

Abrasive Reference - Narrow Range Grades

FEPA Grit Designation Approximate Size in Micrometers (µm) U.S. Standard ASTM E11 BRITISH BS 1987
1181
16/18
14/16
1001
18/20
16/18
851
20/25
18/22
711
25/30
22/25
601
30/35
25/30
501
35/40
30/36
426
40/45
36/44
356
45/50
44/52
301
50/60
52/60
251
60/70
60/72
213
70/80
72/85
181
80/100
85/100
151
100/120
100/120
126
120/140
120/150
107
140/170
150/170
91
170/200
170/200
76
200/230
200/240
64
230/270
240/300
54
270/325
300/350
46
325/400
350/400

Abrasive Reference - Wide Range Grades

FEPA Grit Designation Approximate Size in Micrometers (µm) U.S. Standard ASTM E11 BRITISH BS 1987
1182
16/20
14/18
852
20/30
18/25
602
30/40
25/36
502
35/45
30/44
427
40/50
36/52
252
60/80
60/85


Safety Note: Always follow all manufacturers safety instructions before working with your lathe, or any of the tools or products you may use. If you are unsure about any operation, obtain competent professional instruction before proceeding. Use and wear all necessary safety devices during turning and observe safe woodturning practices to prevent accident or injury.


Steven D. Russell is a professional studio woodturner, teacher and writer. He has written numerous articles for international woodturning magazines, which have been published in more than 78 countries around the world. Steve has demonstrated in numerous cities across the United States. His studio, Eurowood Werks, specializes in bowls, platters and hollow forms with unique visual and tactile treatments.

Steve has also been a regular featured writer for the Guild of Master Craftsman's "Woodturning" magazine, published in London England. Woodturning magazine is the world's leading magazine for woodturners. Look for his articles covering technical topics, or project based articles.


Return From Abrasive Reference Chart to Main Library