Mesh Count
20
Openings per linear inch
Sifting Solutions
20 mesh corresponds to a nominal opening of 850 microns (0.850 mm). In botanical screening, this is generally treated as a coarse separation step for dry sift, pollen, and powder handling lines.
Mesh Count
20
Openings per linear inch
Opening
850 microns
0.850 mm
Opening Inch
0.03346
Nominal clear opening
Open Area
44.8%
Wire diameter 0.420 mm
| Mesh count | 20 |
|---|---|
| Nominal opening (micron) | 850 microns |
| Nominal opening (millimeter) | 0.850 mm |
| Nominal opening (inch) | 0.03346 in |
| Nominal wire diameter | 0.420 mm |
| Nominal open area | 44.8% |
A 20 mesh screen is built with 20 openings per linear inch. For this reference, the clear opening is listed at 850 microns, with a nominal wire diameter of 0.420 mm and an open area near 44.8%. These values are used for engineering comparison, not as a substitute for final supplier drawings.
At 850 microns, this screen size tends to favor high throughput and bulk removal of stems, fibers, and oversized leaf material. In production terms, it sits in the coarse 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
0.850 mm x 1000 = 850 microns
mm from micron
mm = micron / 1000
850 / 1000 = 0.850 mm
Inch conversion
inch = micron / 25400
850 / 25400 = 0.03346 in
Process notes are assembled directly from the selected opening value so each page stays consistent with the table above.
When a 20 mesh screen is used for pollen collection, the nominal opening is 850 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, 20 mesh gives a nominal clear opening of 850 microns. The larger aperture helps with initial break-up and front-end sizing before tighter screening stages are stacked downstream.
In powder grading work, 20 mesh is roughly equivalent to 850 microns. In powder grading, this opening is suited to separating coarse granules from a broader botanical grind.
For botanical pre-screening, a 20 mesh cloth opens at about 850 microns. The screen functions mainly as a pre-screen, removing oversized feed and stabilizing the load sent to the finer mesh train.
18 mesh at 1000 microns will pass a coarser cut and hold higher throughput. 22 mesh at 800 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.