01 — StandardWhat is 450 mesh in microns?
A US standard No. 450 test sieve (ASTM E11) has a nominal opening of 32 µm.
02 — Specifications450 mesh specifications
| Opening (microns) | 32 µm |
| Opening (millimeters) | 0.032 mm |
| Opening (inches) | 0.0013 in |
| US standard sieve | No. 450 |
| Tyler equivalent | 450 mesh |
| Pitch (wire center to center) | 60 µm |
| Typical wire diameter | 0.028 mm |
| Approx. open area | 28% |
03 — ApplicationsWhat is 450 mesh used for?
A 32 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 32 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 450 mesh value is calculated
The name "450 mesh" suggests 450 openings per inch, i.e. a pitch of 25,400 ÷ 450 = 56.4 µm. Standard test sieves, however, are defined by their opening, not by the count: a 32 µm opening woven with the typical 0.028 mm wire gives a real pitch of 32 + 28 = 60 µm, which is about 423.3 wires per inch. That is why mesh numbers and micron values never line up perfectly — and why this site uses the ASTM E11 opening as the answer.
05 — CompareNearby mesh sizes
| Mesh | Microns (µm) | Millimeters | Inches |
|---|---|---|---|
| 300 mesh | ≈ 51 | 0.051 | 0.002 |
| 325 mesh | 45 | 0.045 | 0.0018 |
| 400 mesh | 38 | 0.038 | 0.0015 |
| 450 mesh | 32 | 0.032 | 0.0013 |
| 500 mesh | 25 | 0.025 | 0.001 |
| 600 mesh | ≈ 21.2 | 0.021 | 0.0008 |
| 635 mesh | 20 | 0.02 | 0.0008 |
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.
06 — FAQFrequently asked questions
How many microns is 450 mesh?
450 mesh is 32 µm, which is 0.032 mm or 0.0013 inches.
What size particles pass through a 450 mesh screen?
In a simplified comparison with the nominal opening, particles smaller than about 32 µm can pass a 450 mesh screen. A 32 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 32 µm. Real sieving also depends on particle shape, sieving time and the opening tolerance of the cloth.
What is the open area of 450 mesh?
With a typical 0.028 mm wire, 450 mesh has roughly 28% open area. Thicker wire lowers the open area and the opening size.