EN ISO 4497:2020 specifies a standardized dry sieving method for determining the particle size distribution of metallic powders. Applicable to dry, unlubricated, generally equiaxial metal powders, the method separates a powder sample into size fractions using calibrated wire-cloth test sieves and reports the mass percent retained on each sieve. The standard is not intended for flake-type morphologies or powders that are wholly or mostly under 45 µm.
Key topics and technical requirements
- Test principle: Shake the powder through a stack of sieves arranged by decreasing aperture size; weigh fractions retained on each sieve and the pan.
- Sieve equipment: Use calibrated, non‑magnetic wire cloth sieves mounted in metal frames (nominal diameter 200 mm, depth 25–50 mm). Sieve calibration per ISO 3310‑1 and aperture sizes chosen from ISO 565 principal or intermediate sizes.
- Sample mass: Typically ~100 g for powders with apparent density > 1.50 g/cm3; ~50 g if density ≤ 1.50 g/cm3. Minimum test portion is 10 g if adapting to other frame sizes.
- Sieving mode: Hand sieving or mechanical sieving is allowed; users should note different machines can give different results and may require correlation.
- Sieving end point: Continue until the end point is reached (quantity passing the sieve with the largest retained fraction in 1 min is < 0.1% of the test portion) per ISO 2591‑1, or for an agreed time.
- Weighing and reporting: Use a balance capable of at least 100 g with ±0.05 g accuracy. Record masses to 0.1 g (100 g portions) or 0.05 g (50 g portions). Express each fraction as a percentage of the sum of all fractions to 0.1%; report <0.1% as “trace.” The sum of fractions should be ≥ 98% of the test portion.
- Special handling: If drying is necessary, use vacuum or inert gas for powders that oxidize easily.
Practical applications and users
- Quality control and production monitoring in powder metallurgy, metal powder manufacturing, and additive manufacturing (metal 3D printing).
- Incoming inspection by buyers and suppliers to verify particle size distribution for processability, packing density, flowability, and sintering behavior.
- Testing laboratories and R&D groups using sieve analysis as a routine, low-cost method for coarser metal powders (>45 µm).
- Useful when correlating sieving results with other particle sizing techniques for process optimization.
Related standards
- ISO 565 - Test sieves: nominal sizes of openings
- ISO 3310‑1 - Test sieves: technical requirements and testing
- ISO 2591‑1 - Test sieving methods using woven wire cloth and perforated plate
- Note: EN ISO 4497:2020 supersedes EN 24497:1993
This standard provides a clear, repeatable procedure for dry sieve particle size determination of metallic powders, making it essential for manufacturing, QA, and testing labs working with coarser, equiaxial metal powders.
