Difference Between 40 Mesh and 60 Mesh | Micron Sizes Compared

Every practical choice in filtration and milling starts with particle size, which makes the difference between 40 mesh and 60 mesh the most common decision point. Pick wrong and your pump chokes, your flour yield drops, or your abrasive cuts poorly. Below you’ll find the numbers, the trade-offs, and the selection rule that ends the guesswork.

What 40 Mesh and 60 Mesh Actually Mean

Mesh number refers to the count of openings per linear inch of screen. A 40 mesh screen has 40 openings per inch, and a 60 mesh screen has 60 openings per inch. More openings per inch means smaller holes. Kramer Industries’ mesh size chart confirms that each step in mesh number reduces the opening size noticeably.

The relationship isn’t linear — A quick engineering rule of thumb: Mesh × Microns ≈ 15,000. Check it yourself —

40 Mesh vs 60 Mesh: Side-by-Side Specifications

The table below stacks the key specs so you can compare at a glance. and changes how the screen behaves in real use.

Flow rate and clogging are the practical trade-offs. A 40 mesh screen passes more water or material per minute and needs less cleaning. A 60 mesh screen filters finer particles but slows the system down and requires more frequent maintenance.

How to Choose Between 40 and 60 Mesh

The choice comes down to what particle size you need to remove and whether flow rate or filtration precision matters more. Per AALfilter’s official selection guide, follow these steps to decide:

1. Identify the particle size. Measure the smallest particle you need to catch — use a distribution chart if you’re working with a mixed sample.
2. Define your requirement. For coarse sand removal, stick with 40–60 mesh. For silt or pollen, you’ll need 200–400 mesh instead.
3. Balance efficiency vs. flow rate. Coarse mesh (40) gives higher flow and less clogging but catches fewer particles. Fine mesh (60) removes more but increases pressure drop and cleaning frequency.
4. Pick slightly smaller than your target. Choose a mesh with openings slightly smaller than the particle you want to stop — this gives the best capture without over-filtering.

When you’ve matched the mesh to your particle size and flow needs, your filter will run without excessive clogging or pressure drop, and your material will meet the expected particle distribution.

Common Mistakes When Working With Mesh Sizes

Several misconceptions lead to wrong picks. Knowing them saves time and money.

Confusing linear vs. square inch. Mesh is technically openings per linear inch, though many say “per square inch.” The difference matters when calculating total open area.

Assuming mesh is a precise measurement. A 40 mesh product contains particles around 400 microns, not exactly that size. It’s an average, not a guarantee. Single numbers (60 mesh) indicate an average cut; double numbers (40/60 mean particles fall strictly within that range.

Using 60 mesh for bread wheat flour. In flour milling, 60 mesh is often too fine for standard bread wheat. It drops extraction rates to 65–70%, wasting flour that could have been used. 40 mesh is the better choice for high-extraction bread flour.

Where Each Mesh Size Shines in Practice

Real-world applications cluster around specific mesh sizes. The table below maps common industries to their typical picks and explains why.

Gold prospectors often reach for 40 mesh screens when panning concentrates, and we’ve covered the best 40 mesh gold screens for prospecting in a dedicated roundup if that’s your application.

Why Mesh Number Alone Doesn’t Tell the Full Story

Two screens labeled the same mesh can behave differently depending on wire diameter and weave pattern. The U.S. Standard Mesh system (also called Tyler Mesh) defines the opening size, but the actual flow rate also depends on the material — stainless steel wire, nylon mesh, or polyester all have different open areas at the same mesh count.

For abrasive grading, the mesh number represents the average particle size of the grit. If precise control matters, request a particle distribution report rather than relying on the mesh label alone. And remember that switching from 40 to 60 mesh in an existing filter housing will raise the pressure drop — check your pump’s specifications before making the swap.