A vibratory screen specification sheet lists mesh size, wire diameter, opening size, open area percentage, material grade, frame diameter, and screen type — and understanding each value is essential for ordering the correct replacement screen and optimizing your screening operation. Every number on a spec sheet describes a physical property that affects separation performance, throughput capacity, or equipment compatibility.
Operators and purchasing managers who know how to read screen specs avoid costly mistakes like ordering the wrong mesh, getting an incompatible frame size, or selecting a material grade that does not meet regulatory requirements. At ScreenerKing, we have helped customers interpret screen specifications for more than 30 years. This guide walks through each spec line by line, explains what it means in practical terms, and shows you how to compare specifications across different screen suppliers.
What Is Mesh Size and How Is It Specified?
Mesh size (also called mesh count) is the number of openings per linear inch in a woven wire screen, measured from the center of one wire to a point exactly one inch away. A 20-mesh screen has 20 openings per linear inch. A 100-mesh screen has 100 openings per linear inch. Higher mesh counts mean finer screens with smaller openings.
On a spec sheet, mesh size typically appears as the primary identifier, such as "20 Mesh" or "100M." Some spec sheets use micron notation instead, particularly for very fine screens. Our mesh size conversion chart provides a complete cross-reference between mesh count, micron, and inch measurements for every standard screen size.
Why Is Mesh Count Alone Not Enough to Define a Screen?
Mesh count tells you how many openings per inch, but it does not tell you the actual size of those openings. That depends on the wire diameter. Two 20-mesh screens with different wire diameters will have different opening sizes and different separation cut points. This is why a proper specification always includes both mesh count and wire diameter.
What Does Wire Diameter Tell You?
Wire diameter is the thickness of the individual wire strands that form the mesh. On a spec sheet, it appears in inches (e.g., 0.0169") or millimeters (e.g., 0.43 mm). The wire diameter, combined with the mesh count, determines two critical performance values: the opening size and the open area percentage.
Heavier (thicker) wire produces a more durable screen with smaller openings and lower open area. Lighter (thinner) wire produces larger openings and higher open area but wears faster. If the spec sheet lists a wire grade (light, standard, heavy), that corresponds to specific wire diameters for each mesh count as defined by industry standards.
How Do You Interpret Opening Size?
Opening size (also called aperture) is the actual dimension of each square hole in the mesh, measured as the clear space between adjacent wires. This is the spec that directly defines your separation cut point. Particles smaller than the opening size will pass through; particles larger will not.
Opening size is calculated as:
Opening Size = (1 / Mesh Count) - Wire Diameter
Spec sheets typically list opening size in both inches and microns. Always verify that the opening size matches your target particle size separation. If you need to separate particles at 500 microns, you need an opening size of approximately 500 microns (about 30-35 mesh, depending on wire diameter).
What Does Open Area Percentage Indicate?
Open area percentage represents the fraction of the total screen surface that is open space available for material to pass through. It directly controls throughput capacity. The formula is:
Open Area % = (Opening Size / (Opening Size + Wire Diameter))² × 100
Typical open areas range from about 30% for fine-mesh standard-wire screens to over 55% for coarse-mesh light-wire screens. When comparing screens from different suppliers, the open area tells you which screen will pass more material per square inch of screening surface — a critical factor in screener sizing.
How Do You Identify the Right Material Grade?
The material grade on a screen spec sheet identifies the alloy used to weave the mesh. Each material has different properties that make it suitable for different applications and regulatory environments.
Common Screen Materials Comparison
| Material | Corrosion Resistance | Nickel Content | Magnetic | Common Applications | Regulatory Fit |
|---|---|---|---|---|---|
| 304 Stainless Steel | Good | 8-10.5% | No | Food, general industrial, chemicals | FDA, 3-A, GMP |
| 316 Stainless Steel | Excellent | 10-14% | No | Pharma, corrosive chemicals, marine, salt exposure | FDA, cGMP, USP |
| T430 Stainless Steel | Moderate | 0% (nickel-free) | Yes | Nickel-sensitive products, metal-detectable environments | Allergen compliance, EU nickel regulations |
| Brass | Moderate | 0% | No | Non-sparking environments, specialty applications | ATEX zones |
For a detailed comparison of the three most common stainless steel grades, see our guide on 304 vs. 316 vs. T430 stainless steel.
What Do Frame Size and Frame Type Specifications Mean?
The frame section of a spec sheet tells you the physical dimensions and construction of the screen assembly that mounts inside your vibratory separator. Key frame specifications include:
- Frame outer diameter (OD): Must match your screener's frame ring exactly. Common sizes include 18", 24", 30", 36", 40", 48", and 60".
- Frame inner diameter (ID): The usable screening area inside the frame ring.
- Frame height / depth: Must fit within your screener's deck spacing.
- Frame material: Typically stainless steel or epoxy-coated mild steel.
- Screen type: Pre-tensioned (mesh bonded to frame at factory), field-tensioned (mesh tensioned during installation), or sandwich (two mesh layers with cleaning elements between them).
Frame compatibility is brand-specific. A 30-inch screen for a Sweco separator has different frame dimensions than a 30-inch screen for a Kason or Midwestern Industries unit. ScreenerKing manufactures replacement screens compatible with all major separator brands including Sweco, Kason, Midwestern Industries, Cleveland Vibratory, Russell Finex, and Rotex.
How Do You Identify the Screen Type?
The screen type tells you how the mesh is attached to the frame and whether the screen has any special construction features.
| Screen Type | Construction | Advantages | Best For |
|---|---|---|---|
| Pre-tensioned | Mesh bonded/welded to frame under controlled tension at factory | Consistent tension, fast screen changes, less operator error | Most standard applications, food/pharma, high-volume operations |
| Field-tensioned | Mesh tensioned and secured to frame by operator during installation | Adjustable tension, lower per-screen cost in some cases | Custom meshes, specialty applications, experienced operators |
| Sandwich | Two mesh layers with bouncing balls or sliders between them | Self-cleaning, prevents blinding on fine/sticky materials | Fine mesh, sticky powders, blinding-prone applications |
| Supported | Fine mesh supported by a coarser backing mesh | Prevents sagging on fine mesh, extends screen life | Very fine screening (150 mesh and finer) |
How Do You Compare Screen Specifications from Different Suppliers?
When comparing screens from different manufacturers or suppliers, use this systematic approach:
- Align on mesh count and wire diameter first. These two values determine opening size and open area. If one supplier lists a "20 mesh" screen and another lists "841 micron" — they may be the same screen, but verify the wire diameter to be sure.
- Compare opening sizes in the same units. Convert everything to microns or inches for an apples-to-apples comparison. Small differences in opening size (under 5%) are typically within manufacturing tolerance.
- Verify open area percentages. If one screen has noticeably higher open area, it uses thinner wire. That affects both throughput and durability.
- Confirm material certifications. Not all 304 SS is equal in practice. Ask for mill certifications or material test reports if your application requires verified chemical composition.
- Check frame compatibility. Ensure the frame outer diameter, depth, and mounting style are correct for your specific screener brand and model.
ScreenerKing provides complete specification documentation with every screen order and can supply mill certifications for material traceability when required. Our screens are manufactured to match OEM specifications for compatibility with equipment from Sweco, Kason, Midwestern Industries, Cleveland Vibratory, Russell Finex, and other major brands.
Frequently Asked Questions
What is the most important specification on a vibratory screen?
The opening size is the single value that defines your separation cut point. If the opening size is wrong, the screen will not separate your material correctly regardless of other settings. Always verify opening size — determined by mesh count and wire diameter together — rather than relying on mesh count alone.
How do I know if a screen spec sheet matches my current screen?
Compare all key specifications: mesh count, wire diameter, opening size, material grade, frame outer diameter, and screen type. If any value differs, the screens are not identical. When in doubt, measure your existing screen with calipers and compare to the spec sheet. ScreenerKing's technical team can help you cross-reference specifications using our OEM cross-reference chart.
Why do two screens with the same mesh count have different opening sizes?
Because they use different wire diameters. A 20-mesh screen with light wire (0.012") has a 0.038" opening, while 20-mesh with standard wire (0.0169") has a 0.0331" opening. The mesh count defines openings per inch; the wire diameter determines how much space each wire consumes.
What does the material grade on a screen spec sheet mean?
The material grade identifies the alloy used for the mesh wire. The three most common in vibratory screening are 304 stainless steel (general purpose, food-safe), 316 stainless steel (superior corrosion resistance for chemicals and pharma), and T430 stainless steel (nickel-free, magnetic, for allergen-sensitive and metal-detectable applications).