What are the inspection standards for stainless steel mesh?

The inspection of stainless steel wire mesh must be conducted in accordance with the technical requirements of national standards, utilizing appropriate measuring tools and testing instruments. Quality inspection for stainless steel square-mesh wire cloth is a 100% inspection process; random sampling methods are not employed.

1. Inspection of stainless steel wire diameter, deviation, and material composition

The surface of the stainless steel wire must be smooth and bright, free from defects such as longitudinal drawing marks, burrs, or rust; wire diameter tolerances must comply with specifications, and the material must meet requirements.

2. Inspection of weaving precision

Precision is categorized into three grades: Grade I (maximum mesh deviation ≤ 6%), Grade II (≤ 9%), and Grade III (≤ 12%). Inspection focuses primarily on the arithmetic mean of the mesh size and the dimensions of oversized mesh openings.

3. Inspection of weaving quality

Manufacturing defects are inevitable during the production of stainless steel wire mesh. Generally, for mesh delivered in rolls, major defects are prohibited, while a limited number of significant defects and a certain quantity of minor defects are permissible.

1 Categories of major defects

Major defects primarily include:

(1) Unstable interlacing of warp and weft wires: noticeable loosening or displacement occurs when the wires are rubbed vertically between fingers;

(2) Severe curling: for mesh sizes ≥ 0.18 mm, a natural curl diameter of < 80 mm for a 1-meter length; for mesh sizes < 0.18 mm, a natural curl diameter of < 60 mm for a 1-meter length (classified as non-conforming);

(3) Severe skew: the deviation from perpendicularity between warp and weft wires across the weaving width exceeds 4 degrees;

(4) Extensive creasing (multiple creases over a large area);

(5) Oversized mesh openings (exceeding tolerance limits);

(6) Mesh density deviation over a large area;

(7) Extensive weft displacement (weft slippage) resulting in an uneven mesh surface;

(8) Significant deviation in warp or weft wire diameters;

(9) Holes, broken weft wires (incomplete weft), or large splits/gaps;

(10) Severe, uneven discoloration over a large area or significant mechanical damage. 2 Major Defect Categories

Major defects include:

(1) Splits or holes (breakage of more than 3 warp wires);

(2) Incomplete weft wires (length > 50 mm);

(3) Uneven mesh surface;

(4) Areas of uneven wire spacing (loose or tight bands);

(5) Localized creases, folds, or ripples;

(6) Slight curling;

(7) Slight mesh skew;

(8) Significant skipped wires (length > 10 mm);

(9) Significant loose wires, double wires, or bundled wires (length > 30 mm); ruffled or wavy edges.

3 Minor Defect Categories

Minor defects include slight curling, spot-like oil stains, small foreign objects, slight wavy edges, etc. The number of minor defects must not exceed 5 per 10 square meters.

4 Inspection of Mesh Width and Length

The standard roll length for woven metal wire mesh is 30.5 meters; only a positive tolerance of +0.5 m is permitted (no negative tolerance). Each roll may consist of one to a maximum of three sections, with the shortest section measuring at least 2 meters. For mesh widths up to 2 meters, only a positive tolerance of +20 mm is permitted (no negative tolerance).

5 Inspection of Dutch Weave Mesh (Dense Mesh)

Unlike square-mesh wire cloth, the inspection of aperture size between warp wires and weft wire density is conducted using a steel ruler (1 mm graduation) or a reading microscope (0.05 mm graduation, 25x magnification). Measurements must be taken at a minimum of three locations; lines connecting these points must not run parallel to the warp or weft wires, and measurement points must be at least 20 mm away from the mesh edges. The number of oversized apertures between warp wires must not exceed 3% of the total number of warp wires. Specifications, aperture size deviations, and weft wire density for Dutch weave mesh must comply with national standards. The mesh must be flat and clean; weft wires must be tightly arranged with no gaps or light streaks (gaps allowing light to pass through); and there must be no mechanical damage, creases, rust spots, etc.