400 Mesh to Micron – Opening Size in µm & mm
400 mesh ≈ 37 µm
A US standard 400 mesh sieve has openings of about 37 µm (0.037 mm, 0.0015 in).
Step by step
- Mesh 400 means about 400 openings per linear inch.
- Opening size depends on wire thickness, so it is read from the standard sieve series (ASTM E11).
- 400 mesh ≈ 37 µm.
400 mesh is a fine screen for silt, pigments, fine powders and filtration.
Details
- Opening
- 37 µm
- Millimeters
- 0.037 mm
- Inches
- 0.0015 in
- Compared with a human hair (~70 µm)
- 0.5×
How it works
Mesh number counts the openings per linear inch of a woven screen. Because the wire takes up space, the opening is smaller than 25.4 mm divided by the mesh count, and different wire gauges give different openings — so standard sieve series fix the exact opening for each number. Values here follow the US standard series; Tyler mesh numbers are close but not identical.
Nearby values
Related conversions
Frequently asked questions
What is 400 mesh in microns?
About 37 µm.
What is 400 mesh in mm?
0.037 mm.
Is higher mesh finer?
Yes — more openings per inch means smaller openings.
What is the difference between US and Tyler mesh?
They are two standard series with nearly the same openings; the numbers differ slightly for some sizes.