Mesh Count
18
Openings per linear inch
Sifting Solutions
18 mesh corresponds to a nominal opening of 1000 microns (1.00 mm). In botanical screening, this is generally treated as a coarse separation step for dry sift, pollen, and powder handling lines.
Mesh Count
18
Openings per linear inch
Opening
1000 microns
1.00 mm
Opening Inch
0.03937
Nominal clear opening
Open Area
50.2%
Wire diameter 0.411 mm
| Mesh count | 18 |
|---|---|
| Nominal opening (micron) | 1000 microns |
| Nominal opening (millimeter) | 1.00 mm |
| Nominal opening (inch) | 0.03937 in |
| Nominal wire diameter | 0.411 mm |
| Nominal open area | 50.2% |
A 18 mesh screen is built with 18 openings per linear inch. For this reference, the clear opening is listed at 1000 microns, with a nominal wire diameter of 0.411 mm and an open area near 50.2%. These values are used for engineering comparison, not as a substitute for final supplier drawings.
At 1000 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
1.00 mm x 1000 = 1000 microns
mm from micron
mm = micron / 1000
1000 / 1000 = 1.00 mm
Inch conversion
inch = micron / 25400
1000 / 25400 = 0.03937 in
Process notes are assembled directly from the selected opening value so each page stays consistent with the table above.
When a 18 mesh screen is used for pollen collection, the nominal opening is 1000 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, 18 mesh gives a nominal clear opening of 1000 microns. The larger aperture helps with initial break-up and front-end sizing before tighter screening stages are stacked downstream.
In powder grading work, 18 mesh is roughly equivalent to 1000 microns. In powder grading, this opening is suited to separating coarse granules from a broader botanical grind.
For botanical pre-screening, a 18 mesh cloth opens at about 1000 microns. The screen functions mainly as a pre-screen, removing oversized feed and stabilizing the load sent to the finer mesh train.
16 mesh at 1190 microns will pass a coarser cut and hold higher throughput. 20 mesh at 850 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.