Mesh Count
28
Openings per linear inch
Sifting Solutions
28 mesh corresponds to a nominal opening of 600 microns (0.600 mm). In botanical screening, this is generally treated as a medium separation step for dry sift, pollen, and powder handling lines.
Mesh Count
28
Openings per linear inch
Opening
600 microns
0.600 mm
Opening Inch
0.02362
Nominal clear opening
Open Area
43.7%
Wire diameter 0.307 mm
| Mesh count | 28 |
|---|---|
| Nominal opening (micron) | 600 microns |
| Nominal opening (millimeter) | 0.600 mm |
| Nominal opening (inch) | 0.02362 in |
| Nominal wire diameter | 0.307 mm |
| Nominal open area | 43.7% |
A 28 mesh screen is built with 28 openings per linear inch. For this reference, the clear opening is listed at 600 microns, with a nominal wire diameter of 0.307 mm and an open area near 43.7%. These values are used for engineering comparison, not as a substitute for final supplier drawings.
At 600 microns, this screen size tends to support stable dry separation while still moving material efficiently across the deck. In production terms, it sits in the medium part of the screening range and is usually selected after operators define the target fraction, feed dryness, and deck loading rate.
These formulas explain the unit relationship shown in the table.
Micron from mm
micron = mm x 1000
0.600 mm x 1000 = 600 microns
mm from micron
mm = micron / 1000
600 / 1000 = 0.600 mm
Inch conversion
inch = micron / 25400
600 / 25400 = 0.02362 in
Process notes are assembled directly from the selected opening value so each page stays consistent with the table above.
When a 28 mesh screen is used for pollen collection, the nominal opening is 600 microns. This is usually chosen early in the process to clear large botanical fragments before a finer finishing screen is introduced.
For dry sift separation, 28 mesh gives a nominal clear opening of 600 microns. The larger aperture helps with initial break-up and front-end sizing before tighter screening stages are stacked downstream.
In powder grading work, 28 mesh is roughly equivalent to 600 microns. In powder grading, this opening is suited to separating coarse granules from a broader botanical grind.
For botanical pre-screening, a 28 mesh cloth opens at about 600 microns. The screen can still be used as a controlled pre-screen when the incoming material already has a reasonably narrow particle spread.
26 mesh at 650 microns will pass a coarser cut and hold higher throughput. 30 mesh at 550 microns will shift the cut point finer and tighten material control.
Nominal opening values were curated from commonly referenced industrial wire cloth and U.S. sieve conversion charts. Actual clear opening can vary by weave style, wire diameter, and manufacturing tolerance.
Nominal opening values may vary slightly by weave and wire diameter. For purchase approval, always confirm the actual cloth specification issued by the manufacturer.