Overview
EN ISO 4506:2018 - Hardmetals - Compression test (ISO 4506:2018) is a CEN-endorsed international standard that specifies a laboratory method to determine the ultimate compressive strength (UCS) and proof stress of cemented carbide (hardmetals) under uniaxial compressive loading at room temperature. Prepared by ISO/TC 119 (Powder metallurgy), this 2018 revision updates the original 1979 method and is used for material characterization, quality control and comparative testing of hardmetal grades.
Key topics and technical requirements
- Scope: Measurement of ultimate strength and proof stress of cemented carbides under axial compression.
- Test principle: Axial loading of a cylindrical test piece between two cemented‑carbide (or PCD‑coated) bearing blocks until specified deformation or fracture.
- Apparatus accuracy: Test machine loading error within ±1% across the measuring range.
- Contact anvils: Cemented‑carbide anvils with hardness ≥ 1 800 HV; contact surfaces perpendicular to the load axis and parallel within 0.5 µm/mm.
- Specimen preparation: Test piece dimensions and surface finish requirements are specified (end faces and enlarged‑end cylindrical surfaces ground); minimum diameter measured to ±0.02 mm.
- Loading rate: Uniform rate not exceeding 8 000 N/s (≈100 N/(mm·s)); changes must be gradual and without shock.
- Proof stress determination: Graphic intersection (offset) method (example: 0.2% proof stress); strain measurement using resistive strain gauges (or laser extensometer where applicable). Active gauge length not to exceed 8 mm; two or three gauges recommended.
- Ultimate compressive strength (UCS): Determined by loading to fracture; reported in N/mm².
- Reporting: Arithmetic mean of at least eight determinations; round results to the nearest 10 N/mm². Test report must reference ISO 4506 and include identification, results, and any non‑specified operations or anomalies.
Applications and users
- Quality control and acceptance testing of cemented carbide tooling, inserts and wear parts.
- R&D and material development in powder metallurgy and hardmetal production.
- Metallurgical laboratories evaluating mechanical properties under compression.
- Manufacturers of cutting tools, mining bits, dies and wear components where compressive strength and proof stress are critical.
- Standards and compliance teams ensuring material data is comparable across suppliers and laboratories.
Related standards
- ISO 4506:2018 supersedes earlier editions and is aligned with CEN endorsement as EN ISO 4506:2018.
- ASTM E9 (Compression testing of metallic materials) is referenced as a related method for cylindrical compression specimens.
Keywords: EN ISO 4506:2018, ISO 4506:2018, compression test, hardmetals, cemented carbide, proof stress, ultimate compressive strength, powder metallurgy, CEN, material testing.
