US Grading System
Grade No. US Standard
Micron Range		 Mesh Sizes
1/4 0-1/2 60,000
1/2 0-1 25,000
1 0-2 10,000
2 1-3 9,000
3 2-4 8,500
4 2-6 6,000
6 4-8 3,000
9 6-12 1,800
12 8-15 1,500
15 10-20 1,200
17 15-20 1,100
20 15-25 1,000
25 20-30 880
30 2-36 600

Grade No. US Standard
Micron Range		 Mesh Sizes
35 30-40 500
45 36-54 450
400 35/45 325/400
320 45/53 270/325
240 53/63 230/270
220 63/75 200/230
180 75/90 170/200
150 90/106 140/170
120 106/125 120/140
110 125/150 100/120
105 150/180 80/100
100 180/250 60/80
60 250/300 50/60
46 300/425 40/50

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Powder Size Specifications of the Federation of
European Producers of Abrasive Products (FEPA).
Grit size 3% max.,
larger than,
mcm		 50% min.,
in size range,
mcm 		94% min.,
larger than,
mcm
Grit size 3% max.,
larger than,
mcm		 50% min.,
in size range,
mcm 		94% min.,
larger than,
mcm
F12 2000 N/A 1400 F120 125 N/A 90
F14 1700 N/A 1180 F150 106 N/A 63
F16 1400 N/A 1000 F180 90 N/A 53
F20 1180 N/A 850 F220 75 50.0-56.0 45
F24 850 N/A 600 F240 70 42.5-46.5 28
F30 710 N/A 500 F280 59 35.0-38.0 22
F36 600 N/A 425 F320 49 27.7-30.7 16.5
F40 500 N/A 355 F360 40 21.3-24.3 12
F46 425 N/A 300 F400 32 16.3-18.3 8
F54 355 N/A 250 F500 25 11.8-13.8 5
F60 300 N/A 212 F600 19 8.3-10.3 3
F70 250 N/A 180 F800 14 5.5-7.5 2
F80 212 N/A 150 F1000 10 3.7-5.3 1
F90 180 N/A 125 F1200 7 2.5-3.5 1
F100 150 N/A 106



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FEPA P-Grading System
P Grade D50 Size In Microns FEPA Grade (ref.)
P150 100+/-2.0 F180
P180 77+/-2.0 F220
P220 60+/-2.0 n/a
P240 58.5+/-2.0 F220
P280 52.5+/-2.0 n/a
P320 46.2+/-1.5 F240
P360 40.5+/-1.5 F280
P400 35.0+/-1.5 n/a
P500 30.2+/-1.5 F320
P600 25.8+/-1.0 n/a
P800 21.8+/-1.0 F360
P1000 18.3+/-1.0 F400
P1200 15.3+/-1.0 n/a
P1500 12.6+/-1.0 F500
P2000 10.3+/-0.8 F600
P2500 8.4+/-0.5 n/a

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Standard Testing Sieve Apertures
ASTM Sieve No. ASTM Mesh Opening (mm) Nearest Tyler Sieve Mesh No. Tyler Mesh Opening (mm)
3 6.35 3 6.68
4 4.76 4 4.70
6 3.36 6 3.33
8 2.38 8 2.36
12 1.68 10 1.65
16 1.19 14 1.17
20 0.84 20 0.83
30 0.59 28 0.59
40 0.42 35 0.42
50 0.297 48 0.295
70 0.149 100 0.147
100 0.105 150 0.104
200 0.074 200 >0.074

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