Mesh Count
90
Openings per linear inch
Sifting Solutions
90 mesh corresponds to a nominal opening of 165 microns (0.165 mm). In botanical screening, this is generally treated as a fine separation step for dry sift, pollen, and powder handling lines.
Mesh Count
90
Openings per linear inch
Opening
165 microns
0.165 mm
Opening Inch
0.00650
Nominal clear opening
Open Area
34.2%
Wire diameter 0.117 mm
| Mesh count | 90 |
|---|---|
| Nominal opening (micron) | 165 microns |
| Nominal opening (millimeter) | 0.165 mm |
| Nominal opening (inch) | 0.00650 in |
| Nominal wire diameter | 0.117 mm |
| Nominal open area | 34.2% |
A 90 mesh screen is built with 90 openings per linear inch. For this reference, the clear opening is listed at 165 microns, with a nominal wire diameter of 0.117 mm and an open area near 34.2%. These values are used for engineering comparison, not as a substitute for final supplier drawings.
At 165 microns, this screen size tends to tighten the cut point so finer resin-rich fractions can be graded with less oversized carryover. In production terms, it sits in the fine 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
0.165 mm x 1000 = 165 microns
mm from micron
mm = micron / 1000
165 / 1000 = 0.165 mm
Inch conversion
inch = micron / 25400
165 / 25400 = 0.00650 in
Process notes are assembled directly from the selected opening value so each page stays consistent with the table above.
When a 90 mesh screen is used for pollen collection, the nominal opening is 165 microns. This range is often selected when operators want a cleaner pass while still keeping a usable collection rate.
For dry sift separation, 90 mesh gives a nominal clear opening of 165 microns. At this point the screen is acting as a fine classification layer, so feed consistency and blinding control become more important.
In powder grading work, 90 mesh is roughly equivalent to 165 microns. This opening fits controlled grading steps where mid-size powder fractions need to be standardized before packaging or blending.
For botanical pre-screening, a 90 mesh cloth opens at about 165 microns. At this fineness the screen is no longer a rough pre-screen. It becomes a precision control point inside a multi-stage grading workflow.
80 mesh at 180 microns will pass a coarser cut and hold higher throughput. 100 mesh at 150 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.