Mesh Count
45
Openings per linear inch
Sifting Solutions
45 mesh corresponds to a nominal opening of 355 microns (0.355 mm). In botanical screening, this is generally treated as a medium separation step for dry sift, pollen, and powder handling lines.
Mesh Count
45
Openings per linear inch
Opening
355 microns
0.355 mm
Opening Inch
0.01398
Nominal clear opening
Open Area
39.6%
Wire diameter 0.209 mm
| Mesh count | 45 |
|---|---|
| Nominal opening (micron) | 355 microns |
| Nominal opening (millimeter) | 0.355 mm |
| Nominal opening (inch) | 0.01398 in |
| Nominal wire diameter | 0.209 mm |
| Nominal open area | 39.6% |
A 45 mesh screen is built with 45 openings per linear inch. For this reference, the clear opening is listed at 355 microns, with a nominal wire diameter of 0.209 mm and an open area near 39.6%. These values are used for engineering comparison, not as a substitute for final supplier drawings.
At 355 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
0.355 mm x 1000 = 355 microns
mm from micron
mm = micron / 1000
355 / 1000 = 0.355 mm
Inch conversion
inch = micron / 25400
355 / 25400 = 0.01398 in
Process notes are assembled directly from the selected opening value so each page stays consistent with the table above.
When a 45 mesh screen is used for pollen collection, the nominal opening is 355 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, 45 mesh gives a nominal clear opening of 355 microns. This range suits balanced production lines that need separation accuracy without sacrificing deck productivity.
In powder grading work, 45 mesh is roughly equivalent to 355 microns. In powder grading, this opening is suited to separating coarse granules from a broader botanical grind.
For botanical pre-screening, a 45 mesh cloth opens at about 355 microns. The screen can still be used as a controlled pre-screen when the incoming material already has a reasonably narrow particle spread.
40 mesh at 400 microns will pass a coarser cut and hold higher throughput. 46 mesh at 350 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.