Overview
ISO 6106:2013 - Abrasive products - Checking the grain size of superabrasives - specifies a laboratory method for determining or checking the grain size of superabrasives (diamond or cubic boron nitride, CBN) used in industrial products such as grinding wheels and saws. The standard defines grain size designations, allowable particle-size limits, the required sieves, and a repeatable sieving procedure to assess particle-size distribution exclusive of any coating.
Key topics and technical requirements
- Scope and purpose: Method for checking grain size of diamond (D) and cubic boron nitride (B) grains and assigning ISO grain designations (see Tables 2 and 3).
- Apparatus:
- Test-sieving machines that provide reproducible results (e.g., in accordance with ISO 9284).
- Electroformed precision sieves (200 mm or 75 mm diameter) with square apertures and a supporting grid (≈2.2 lines/cm) to prevent particle sliding.
- Adaptors for 75 mm sieves (specified in Annex A).
- Sampling and sample mass: Use representative sampling techniques (blending, sample splitters) to obtain the test mass specified in the standard.
- Test conditions: Conditioning per ISO 554 - nominally 23 °C ±2 °C and 50 % ±5 % relative humidity.
- Sieving procedure:
- Assemble nested sieves from coarsest to finest with pan and cover.
- Sieving time: 15 minutes on an approved sieve shaker.
- Remove and weigh oversize, on‑size and undersize fractions; electroformed sieves cleaned ultrasonically where needed.
- Measurement precision:
- Balance precision: at least 0.01 g for 200 mm sieves and 0.001 g for 75 mm sieves.
- Timer accuracy: ±1 % over 15 minutes.
- Evaluation and designation:
- Calculate percent retained per fraction relative to cumulative mass; repeat if total