ISO 11124-3:2018

Overview

ISO 11124-3:2018 specifies requirements for high‑carbon cast‑steel shot and grit used as metallic blast‑cleaning abrasives in surface preparation. The standard covers 14 shot grades and 11 grit grades supplied in the new condition and defines limits for particle size, hardness, apparent density, defects, microstructure, chemical composition and moisture. It is intended for use in both static and site blasting equipment and is commonly selected where recovery and re‑use of abrasives is practiced.

Key Topics and Requirements

• Designation and grading: Products are identified using the format e.g. Abrasive ISO 11124 M/HCS/S140 (M/HCS = metallic high‑carbon cast‑steel; S = shot, G = grit; 3‑digit grade = nominal particle size ×100).
• Particle size: Screening specifications by grade (see Tables 1–2) define cumulative percent retained for shot and grit grades; sampling per ISO 11125‑1 and sizing by ISO 11125‑2.
• Hardness: At least 90% of tested particles shall fall within one of the standard Vickers ranges: 390–530 HV, 470–610 HV, 570–710 HV, or ≥700 HV; purchaser can specify special hardness ranges.
• Apparent density: Minimum apparent density of 7.0 kg/dm³ (≈7 000 kg/m³) measured per ISO 11125‑4.
• Defect limits and microstructure: Defined maximums for non‑round particles, voids, shrinkage, cracks and total defects (e.g., total defects: shot max 20%, grit max 40%), and microstructure requirements (uniform martensite and/or bainite; max 15% undesirable microstructure) per ISO 11125‑5.
• Chemical composition & moisture: Carbon 0.80–1.20%, manganese 0.35–1.20%, silicon ≥0.40%, sulfur ≤0.05%, phosphorus ≤0.05%; moisture ≤0.2% (ISO methods referenced).
• Packaging & traceability: Full product coding and lot identification required on sale units and sub‑units; test reports available on request.

Applications and Who Uses It

• Target users: abrasive manufacturers, surface‑preparation contractors, paint/coating specifiers, quality assurance laboratories, procurement teams and steel fabricators.
• Typical uses: blast cleaning of steel substrates prior to painting or coating, in both fixed blast rooms and on‑site blasting. Although developed for steelwork, properties are often suitable for preparing other materials when blast‑cleaning per ISO 8504‑2.
• Practical benefits: ensures consistent abrasive performance, supports abrasive recovery/re‑use strategies, and provides measurable quality criteria for procurement and QA.

Related Standards (if applicable)

• ISO 11125 series - test methods for metallic blast‑cleaning abrasives (sampling, sizing, hardness, density, defects, foreign matter, moisture)
• ISO 8504‑2 - description of blast‑cleaning techniques
• Annex A of ISO 11124‑3 maps approximate equivalences to national metallic abrasive codings.

Keywords: ISO 11124-3:2018, high‑carbon cast‑steel shot and grit, metallic blast‑cleaning abrasives, surface preparation, abrasive grading, hardness ranges, particle size distribution, ISO 11125, quality control.