Converting between mesh numbers and micron opening sizes is one of the most frequent tasks in vibratory screening specification. Whether you're ordering replacement screens, writing a material specification, or trying to match a competitor's equipment, understanding the relationship between Tyler mesh, US Standard mesh, microns, millimeters, and inches is essential.
Use the interactive calculator below to convert instantly between any mesh or micron value. The full reference conversion table below the calculator is the primary reference for all ScreenerKing screen specifications and is the most comprehensive free mesh-to-micron reference available for industrial screening applications.
What Is the Difference Between Mesh Number and Microns?
Mesh number is a count: the number of wire openings per linear inch in a woven wire screen. A screen labeled 40 mesh has 40 individual openings per inch measured in any direction across the screen surface. Micron (abbreviated µm) is a unit of actual physical length — one millionth of a meter — used to describe the size of the opening itself.
The relationship between mesh number and micron opening is not a simple formula because the wire diameter also affects the aperture size. Two screens with the same mesh number but different wire diameters will have different micron openings. This is why the Tyler series and US Standard (ASTM E11) series — which use different wire gauges — produce different aperture sizes at the same mesh number, particularly at finer mesh sizes.
Tyler Mesh vs. US Standard Mesh: Key Differences
Tyler mesh was developed by W.S. Tyler and is the traditional standard used in North American mining, aggregate, and industrial classification. US Standard mesh (ASTM E11) is the more recent national standard and is used in laboratory sieves, pharmaceutical specifications, and most modern industrial screening specifications. ISO 3310 and ISO 565 provide the metric equivalents used in European and international applications.
For most production screening applications, the differences between Tyler and US Standard mesh are small and do not affect process performance. However, when ordering replacement screens, always specify the standard (Tyler or ASTM E11) that your screener manufacturer used to ensure the correct wire diameter and opening size are supplied.
Complete Mesh-to-Micron Conversion Table
This table covers the full range of mesh sizes used in industrial vibratory screening, from very coarse 4 mesh (wire opening 4,760 microns) to ultrafine 500 mesh (25 microns). Values shown are nominal aperture openings per each standard. For sieve analysis specifications requiring tolerance data, refer to ASTM E11 (US Standard) or ISO 3310-1 (metric).
| Tyler Mesh | US Standard Mesh (ASTM E11) | Opening (µm) | Opening (mm) | Opening (inches) | ISO/Metric (mm) |
|---|---|---|---|---|---|
| 4 | 4 | 4,760 | 4.76 | 0.187 | 4.75 |
| 5 | 5 | 4,000 | 4.00 | 0.157 | 4.00 |
| 6 | 6 | 3,360 | 3.36 | 0.132 | 3.35 |
| 7 | 7 | 2,830 | 2.83 | 0.111 | 2.80 |
| 8 | 8 | 2,380 | 2.38 | 0.0937 | 2.36 |
| 9 | 10 | 2,000 | 2.00 | 0.0787 | 2.00 |
| 10 | 10 | 1,680 | 1.68 | 0.0661 | 1.70 |
| 12 | 12 | 1,410 | 1.41 | 0.0555 | 1.40 |
| 14 | 14 | 1,190 | 1.19 | 0.0469 | 1.18 |
| 16 | 16 | 1,000 | 1.00 | 0.0394 | 1.00 |
| 20 | 18 | 841 | 0.841 | 0.0331 | 0.850 |
| 24 | 20 | 707 | 0.707 | 0.0278 | 0.710 |
| 28 | 25 | 595 | 0.595 | 0.0234 | 0.600 |
| 32 | 30 | 500 | 0.500 | 0.0197 | 0.500 |
| 35 | 35 | 420 | 0.420 | 0.0165 | 0.425 |
| 42 | 40 | 354 | 0.354 | 0.0139 | 0.355 |
| 48 | 45 | 297 | 0.297 | 0.0117 | 0.300 |
| 60 | 50 | 250 | 0.250 | 0.0098 | 0.250 |
| 65 | 60 | 210 | 0.210 | 0.0083 | 0.212 |
| 80 | 70 | 177 | 0.177 | 0.0070 | 0.180 |
| 100 | 80 | 149 | 0.149 | 0.0059 | 0.150 |
| 115 | 100 | 125 | 0.125 | 0.0049 | 0.125 |
| 150 | 120 | 105 | 0.105 | 0.0041 | 0.106 |
| 170 | 140 | 88 | 0.088 | 0.0035 | 0.090 |
| 200 | 170 | 74 | 0.074 | 0.0029 | 0.075 |
| 250 | 200 | 63 | 0.063 | 0.0025 | 0.063 |
| 270 | 230 | 53 | 0.053 | 0.0021 | 0.053 |
| 325 | 270 | 44 | 0.044 | 0.0017 | 0.045 |
| 400 | 325 | 37 | 0.037 | 0.0015 | 0.038 |
| 500 | 400 | 25 | 0.025 | 0.0010 | 0.025 |
Common Application Reference: Which Mesh Size for Which Industry?
| Application | Typical Mesh Range | Opening (µm) | Notes |
|---|---|---|---|
| Coarse aggregate scalping | 4–8 mesh | 2,380–4,760 | Top-deck oversize removal |
| Plastic pellet grading | 5–12 mesh | 1,410–4,000 | Two-deck: oversize top, fines bottom |
| Organic matter / compost | 8–16 mesh | 1,000–2,380 | Coarse debris scalping |
| Bread / all-purpose flour | 20–30 mesh | 595–841 | Contaminant removal, aeration |
| Cannabis trim scalping | 30 mesh | 595 | Remove large leaf material |
| Spice powders | 30–40 mesh | 400–595 | Lump removal, contaminant check |
| Nutraceutical capsule fill | 30–60 mesh | 250–595 | Depends on capsule size |
| Activated carbon | 30–80 mesh | 177–595 | Grade classification |
| Sugar, crystalline | 40–80 mesh | 177–400 | Grade classification by crystal size |
| Animal feed pellets | 8–16 mesh | 1,000–2,380 | Fines removal before packaging |
| Coffee grounds (fine) | 50–70 mesh | 210–297 | Grind consistency check |
| Cannabis kief (Grade A) | 100–150 mesh | 100–150 | Full trichome heads |
| Pharmaceutical API | 60–200 mesh | 74–250 | Depends on target particle size |
| Cocoa powder | 100–140 mesh | 105–149 | Agglomerate removal |
| Metal powder (coarse) | 60–100 mesh | 149–250 | Grade classification |
| Metal powder (fine) | 200–325 mesh | 44–74 | Additive manufacturing grades |
| Toner / reprographics | 270–325 mesh | 44–53 | Fine particle QC |
| Starch slurry (wet) | 100–200 mesh | 74–149 | Wet screening only |
How to Use the Mesh-to-Micron Converter
Enter a known value in any field — Tyler mesh, US Standard mesh, microns, millimeters, or inches — and the calculator returns all equivalent values from the complete ASTM E11 and Tyler reference tables. The tool highlights the nearest standard sieve size when your input falls between standard sizes, and identifies the ScreenerKing replacement screen that matches your specification.
If you are specifying a screen for a new application and need advice on which mesh size is appropriate for your material and separation goal, use our Screen Selection Quiz to get a recommendation, or contact ScreenerKing directly for application engineering support.
Frequently Asked Questions: Mesh-to-Micron Conversion
What is the difference between mesh and microns?
Mesh number counts openings per linear inch; microns measure the physical size of each opening in millionths of a meter. Higher mesh numbers mean more, smaller openings and a smaller micron value. The two are related but not simply proportional because wire diameter also affects the opening size.
What is the difference between Tyler mesh and US mesh?
Tyler mesh and US Standard mesh (ASTM E11) use slightly different wire diameters, producing slightly different aperture sizes at the same mesh number. Tyler is the older standard common in mining. ASTM E11 is the modern standard used in labs and most industrial specifications. Differences are small (under 5%) for most practical applications.
How do I convert mesh to microns without a calculator?
For 20 to 400 US mesh, the approximation Microns ≈ 15,000 ÷ Mesh Number is accurate within 10%. For example, 100 mesh ≈ 150 microns (actual is 149 microns). Use the full reference table above for precise engineering specifications.
What mesh size do I need to separate 200-micron particles?
Use 70 US mesh (212 micron opening) to retain particles above 200 microns, or 80 mesh (177 micron opening) for a tighter cut just below 200 microns. For precise separations, specify the ASTM E11 nominal aperture rather than relying on the mesh number alone.
Does screen mesh size affect throughput?
Yes. Finer mesh screens have less open area per square foot of screen surface. Halving the aperture size typically reduces throughput to 25 to 40 percent of the coarser mesh value for the same material. Compensate with a larger screener, multiple units in parallel, or ultrasonic transducers to maintain open area.