Newsgroups: rec.pyrotechnics
From: nelson@cs.rochester.edu (Randal Nelson)
Subject: Re: Mesh
Date: Thu, 14 Mar 1996 16:41:32 GMT

>What are the basic mesh sizes?  Where can they be purchased?  What is the
>size that is one size bigger than air float charcoal.  I would appreciate
>some help here.

This question keeps coming up, so here it is, straight from the CRC,
More information than you ever wanted to know about mesh standards.

Big ones are used in the gravel and concrete industry.
Note how the ratio of the wire diameter to the opening varies from less
than 1/10 for a 5 inch sieve, to nearly one for a #400 mesh.

Finer meshes than 400 (600) are very difficult to make, and other methods
than screens are used for separating finer powders such as some used
in pyrotechnic compositions.

STANDARD TEST SIEVES (WIRE CLOTH)


Designation     Nominal   Permissible    Maximum     Maximum      Nominal
                Opening   Variation of   Opening     Individual   Wire
                          Average        for not     Opening      Diameter
                          Opening        more than
                                         5 percent
--------------------------------------------------------------------------
125mm   5.0in   5in       +-3.7mm        130mm       130.9mm      8.0mm
106mm   4.24in  4.24in    +-3.2mm        110.2mm     111.1mm      6.40mm
100mm   4.0in   4.0in     +-3.0mm        104.0mm     104.8mm      6.30mm
90mm    3.5in   3.5in     +-2.7mm        93.6mm      94.4mm       6.08mm
75mm    3.0in   3.0in     +-2.2mm        78.1mm      78.7mm       5.80mm
63mm    2.5in   2.5in     +-1.9mm        65.6mm      66.2mm       5.50mm
53mm    2.12in  2.12in    +-1.6mm        55.2mm      55.6mm       5.15mm
50mm    2.0in   2.0in     +-15.mm        52.1mm      52.6mm       5.05mm
45mm    1.75in  1.75in    +-1.4mm        46.9mm      47.4mm       4.85mm
37.5mm  1.5in   1.5in     +-1.1mm        39.1mm      39.5mm       4.59mm
31.5mm  1.25in  1.25in    +-1.0mm        32.9mm      33.2mm       4.23mm
26.5mm  1.06in  1.06in    +-.8mm         27.7mm      28.0mm       3.90mm
25.0mm  1.0in   1.0in     +-.8mm         26.1mm      26.4mm       3.80mm
22.4mm  7/8in   .875in    +-.7mm         23.4mm      23.7mm       3.50mm
19.0mm  3/4in   .75in     +-.6mm         19.9mm      20.1mm       3.30mm
16.0mm  5/8in   .625in    +-.5mm         16.7mm      17.0mm       3.00mm
13.2mm  .530in  .530in    +-.41mm        13.83mm     14.05mm      2.75mm
12.5mm  1/2in   .50in     +-.39mm        13.10mm     13.31mm      2.67mm
11.2mm  7/16in  .438in    +-.35mm        11.75mm     11.94mm      2.45mm
9.5mm   3/8in   .375in    +-.30mm        9.97mm      10.16mm      2.27mm
8.0mm   5/16in  .312in    +-.25mm        8.41mm      8.58mm       2.07mm
6.7mm   .265in  .265in    +-.21mm        7.05mm      7.20mm       1.87mm
6.3mm   1/4in   .250in    +-.20mm        6.64mm      6.78mm       1.82mm
5.6mm   # 3.5   .223in    +-.18mm        5.9mm       6.04mm       1.68mm
4.75mm  # 4     .187in    +-.15mm        5.02mm      5.14mm       1.54mm
4.00mm  # 5     .157in    +-.13mm        4.23mm      4.35mm       1.37mm
3.35mm  # 6     .132in    +-.11mm        3.55mm      3.66mm       1.23mm
2.80mm  # 7     .111in    +-.095mm       2.975mm     3.070mm      1.10mm
2.36mm  # 8     .0937in   +-.080mm       2.515mm     2.600mm      1.00mm
2.00mm  # 10    .0787in   +-.070mm       2.135mm     2.215mm      .900mm
1.70mm  # 12    .0661in   +-.060mm       1.820mm     1.890mm      .810mm
1.40mm  # 14    .0555in   +-.050mm       1.505mm     1.565mm      .725mm
1.18mm  # 16    .0469in   +-.045mm       1.270mm     1.330mm      .650mm
1.00mm  # 18    .0394in   +-.040mm       1.080mm     1.135mm      .580mm
.850mm  # 20    .0331in   +-.035mm       .925mm      .970mm       .510mm
.750mm  # 25    .0278in   +-.030mm       .775mm      .815mm       .450mm
.600mm  # 30    .0234in   +-.025mm       .660mm      .695mm       .390mm
.500mm  # 35    .0197in   +-.020mm       .550mm      .585mm       .340mm
.425mm  # 40    .0165in   +-.019mm       .471mm      .502mm       .290mm
.355mm  # 45    .0139in   +-.016mm       .396mm      .425mm       .247mm
.300mm  # 50    .0117in   +-.014mm       .337mm      .363mm       .215mm
.250mm  # 60    .0098in   +-.012mm       .283mm      .306mm       .180mm
.212mm  # 70    .0083in   +-.010mm       .242mm      .263mm       .152mm
.180mm  # 80    .0070in   +-.009mm       .207mm      .227mm       .131mm
.150mm  # 100   .0059in   +-.008mm       .174mm      .192mm       .110mm
.125mm  # 120   .0049in   +-.007mm       .147mm      .163mm       .091mm
.106mm  # 140   .0041in   +-.006mm       .126mm      .141mm       .076mm
.090mm  # 170   .0035in   +-.005mm       .108mm      .122mm       .064mm
.075mm  # 200   .0029in   +-.005mm       .091mm      .103mm       .053mm
.063mm  # 230   .0025in   +-.004mm       .077mm      .089mm       .044mm
.053mm  # 270   .0021in   +-.004mm       .066mm      .076mm       .037mm
.045mm  # 325   .0017in   +-.003mm       .057mm      .066mm       .030mm
.038mm  # 400   .0015mm   +-.003mm       .048mm      .057mm       .025mm


RN

I love the smell of Cesium in the morning!!!

-- 
  Randal Nelson			 716-275-8488	University of Rochester
		      nelson@cs.rochester.edu	Computer Science Department
..!{allegra,decvax,rutgers}!rochester!nelson	Rochester, New York,  14627