01 — StandardWhat is 300 mesh in microns?
300 mesh is not a standard test sieve number, so there is no official opening. With an assumed 33.7 µm wire (interpolated between ASTM E11 sieves), the opening is about 51 µm. Real wire cloth varies, so check the supplier's spec.
02 — Specifications300 mesh specifications
| Opening (microns) | ≈ 51 µm |
| Opening (millimeters) | 0.0509974 mm |
| Opening (inches) | 0.00200777 in |
| US standard sieve | Not a standard size |
| Tyler equivalent | — |
| Pitch (wire center to center) | 84.7 µm |
| Assumed wire diameter | 0.0336693 mm |
| Approx. open area | 36% |
03 — ApplicationsWhat is 300 mesh used for?
The 51 µm opening falls within the silt (3.9 µm–62.5 µm) class of the Wentworth grain-size scale. Comparing grain size with the nominal opening only: very fine sand and coarser would be retained; silt is split at about 51 µm. Real sieving also depends on particle shape, sieving time and the opening tolerance of the cloth.
We have no sourced application data for openings this size yet.
Ranges show common practice with sources on the mesh size by application page — always check your equipment maker's recommendation.
04 — CalculationHow the 300 mesh value is calculated
300 openings per inch gives a pitch of 25,400 ÷ 300 = 84.7 µm. Subtracting an assumed 33.7 µm wire (interpolated between ASTM E11 sieves) leaves an opening of about 51 µm. Change the wire diameter in the calculator above to match your screen.
Before display rounding: 50.9973995286009 µm opening with 0.0336693 mm assumed wire. The main estimate uses three significant digits; unit conversions retain more digits.
05 — CompareNearby mesh sizes
| Mesh | Microns (µm) | Millimeters | Inches |
|---|---|---|---|
| 230 mesh | 63 | 0.063 | 0.0025 |
| 250 mesh | 63 | 0.063 | 0.0025 |
| 270 mesh | 53 | 0.053 | 0.0021 |
| 300 mesh | ≈ 51 | 0.0509974 | 0.00200777 |
| 325 mesh | 45 | 0.045 | 0.0018 |
| 400 mesh | 38 | 0.038 | 0.0015 |
| 450 mesh | 32 | 0.032 | 0.0013 |
Values are ASTM E11 nominal openings (Tyler equivalents for 150 and 250 mesh). Italic ≈ values are estimates for non-standard mesh counts, calculated from the mesh count and an assumed wire diameter (interpolated between ASTM E11 sieves, or extrapolated beyond No. 635). Wire values are ASTM E11 typical wire for standard sizes.Data sources and review limits.
06 — FAQFrequently asked questions
How many microns is 300 mesh?
300 mesh is ≈ 51 µm, which is 0.0509974 mm or 0.00200777 inches.
What size particles can pass through 300-mesh screens?
In a simplified comparison with the nominal opening, particles smaller than about 51 µm can pass through 300-mesh screens. The 51 µm opening falls within the silt (3.9 µm–62.5 µm) class of the Wentworth grain-size scale. Comparing grain size with the nominal opening only: very fine sand and coarser would be retained; silt is split at about 51 µm. Real sieving also depends on particle shape, sieving time and the opening tolerance of the cloth.
What is the open area of 300 mesh?
With an assumed 0.0336693 mm wire, 300 mesh has roughly 36% open area. Thicker wire lowers the open area and the opening size.