Mesh Size

The term ‘Mesh’ is used to describe the size of an abrasive particle. In some instances, such as with Aluminum Oxide Grit or Silicon Carbide Grit, a single number is used. This does not mean every particle in that product is exactly that size but rather than mesh size indicator is approximately the mean or average size of the range of particles in that grade. In other instances, such as with Walnut Shell Grit or Glass Beads, two numbers are used. This indicates that all of the particles in that grade of product are within that range of mesh sizes.

Contained below is more detail about Mesh size, how that is related to the grit size, and what these terms mean as it relates to abrasive (and non-abrasive) products.

What is Mesh Size?

U.S. Mesh Size (or U.S. Sieve Size) is defined as the number of openings in one square inch of a screen. For example, a 36 mesh screen will have 36 openings while a 150 mesh screen will have 150 openings. Since the size of screen (one square inch) is constant, the higher the mesh number the smaller the screen opening and the smaller the particle that will pass through. Generally US Mesh is measured using screens down to a 325 mesh (325 openings in one square inch).

Sometimes the mesh size of a product in noted with either a minus (-) or plus (+) sign. These signs indicate that the particles are either all smaller than (-) or all larger than (+) the mesh size. For example, a product identified as -100 mesh would contain only particles that passed through a 100 mesh screen. A +100 grade would contain particles that did not pass through a 100 mesh screen. When a grade of product is noted with a dash or a slash is indicates that the product has particle contained within the two mesh sizes. For example, a 30/70 or 30-70 grade would only have particles that are smaller than 30 mesh and larger than 70 mesh.

Mesh vs. Grit

The terms Mesh and Grit are often confused. The terms can be used interchangeably when referring to abrasive grit. A 60 mesh Aluminum Oxide can also correctly be termed a 60 grit Aluminum Oxide. In practical terms, identifying a specific abrasive product with the term 60 Mesh would normally indicate that the product has a median size of the openings on a 60 mesh screen. The term 60 Grit more accurately identifies the particle size distribution of the product but the difference in terminology is insignificant for industry purposes. See our blog post Mesh vs. Grit for more detail.

Mesh Conversion Chart

The chart below shows the approximate size in inches and microns for various mesh sizes. These values are generally accepted as accurate but are approximates because the thickness of the wire used to make a specific screen will vary the number of openings in the one square inch. A micron is one-millionth of a meter or one-twenty-five thousandths of an inch. Most grades below 325 mesh are indicated by the micron size as these sizes are not manufactured using screens.

US Mesh



4 4,750 um 0.187
5 4,000 um 0.157
6 3,350 um 0.132
7 2,800 um 0.111
8 2,360 um 0.0937
10 2,000 um 0.0787
12 1,700 um 0.0661
14 1,400 um 0.0555
16 1,200 um 0.0473
18 1,000 um 0.0394
20 850 um 0.0331
24 690 um 0.027
30 560 um 0.022
36 485 um 0.019
40 425 um 0.016
46 355 um 0.014
54 305 um 0.012
60 250 um 0.01
70 210 um 0.0083
80 165 um 0.0065
90 145 um 0.0057
100 149 um 0.0059
120 125 um 0.0049
140 105 um 0.0041
150 89 um 0.0035
170 88 um 0.0031
180 76 um 0.003
200 75 um 0.0029
220 63 um 0.0025
240 53 um 0.002
280 44 um 0.0015
320 36 um 0.0012
400 23 um 0.00087
500 19 um 0.00075
600 16 um 0.00063
800 12 um 0.00047
1,000 9 um 0.00028
1,200 6 um 0.00024

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