U.S. Standard Sieve Sizes



                                        U.S. Standard
                                          Sieve Mesh #                          Millimeters                            Microns                                     Phi

Wire Squares
4096
 
-12
Wire Squares
1024
-10
Wire Squares
256
 
-8
Wire Squares
64
-6
Wire Squares
16
-4
5
4
-2
6
3.36
-1.75
7
2.83
-1.5
8
2.38
-1.25
10
2.00
-1.0
12
1.68
-0.75
14
1.41
-0.5
16
1.19
-0.25
18
1.00
0.0
20
0.84
0.25
25
0.71
0.5
30
0.59
0.75
35
0.50
500
1.0
40
0.42
420
1.25
45
0.35
350
1.5
50
0.30
300
1.75
60
0.25
250
2.0
70
0.210
210
2.25
80
0.177
177
2.5
100
0.149
149
2.75
120
0.125
125
3.0
140
0.105
105
3.25
170
0.088
88
3.5
200
0.074
74
3.75
230
0.0625
62.5
4.0
270
0.053
53
4.25
325
0.044
44
4.5
Hydrometer (or Pipette)
0.037
37
4.75
Hydrometer (or Pipette)
0.031
31
5.0
Hydrometer (or Pipette)
0.0156
15.6
6.0
Hydrometer (or Pipette)
0.0078
7.8
7.0
Hydrometer (or Pipette)
0.0039
3.9
8.0
Hydrometer (or Pipette)
0.0020
2.0
9.0
Hydrometer (or Pipette)
0.00098
0.98
10.0
Hydrometer (or Pipette)
0.00049
0.49
11.0
Hydrometer (or Pipette)
0.00024
0.24
12.0
Hydrometer (or Pipette)
0.00012
0.12
13.0
Hydrometer (or Pipette)
0.00006
0.06
14.0
Table 1 : Scales used to compare grain size.