Overview
EN ISO 4957:2018 (Tool steels) is the CEN-adopted international standard that specifies requirements for wrought tool steels, including non‑alloy cold‑work, alloy cold‑work, alloy hot‑work, and high‑speed tool steels. Published as ISO 4957:2018 and adopted by CEN in July 2018, the standard applies to hot‑rolled, forged, cold‑drawn, cold‑rolled and powder‑metallurgy products supplied in defined surface and heat‑treatment delivery conditions.
Key topics and technical requirements
The standard organizes technical requirements and guidance for tool steel selection, production and delivery. Major topics include:
- Classification and designation of tool steel grades (aligned with ISO 4948‑1 and ISO/TS 4949).
- Scope of grades covered (tables listing internationally important steels; availability may vary by country).
- Manufacturing and delivery conditions, including heat‑treatment and surface conditions to be declared on delivery (see clause 6.2 and Table 1).
- Chemical composition and mechanical properties requirements for each grade.
- Surface quality and finish requirements, referencing ISO 9443 (bars/wire rod) and ISO 7788 (plates/wide flats).
- Dimensions, tolerances and shape requirements for bars, plates and other product forms.
- Inspection, testing and conformance, including sampling, test methods (Brinell and Rockwell hardness per ISO 6506‑1 and ISO 6508‑1), retests, sorting and reprocessing.
- Marking and documentation, with inspection documents per ISO 10474.
- Informative and normative annexes, e.g. hardness–tempering curves (Annex A), supplementary requirements (Annex B) and comparable steel designations (Annex C).
Practical applications
EN ISO 4957 is used to ensure consistent material selection and quality control for tools and tooling components where hardness, wear resistance and toughness are critical. Typical applications include:
- Dies, punches and forming tools (cold‑work and hot‑work tooling)
- Cutting tools and inserts (high‑speed tool steels)
- Moulds and tools for glass and high‑temperature forming (where ISO 4955 may be referenced)
- Precision gauges, measuring tools and handling tools requiring controlled hardness and surface finish
Who uses this standard
- Material and steel suppliers specifying and certifying tool‑steel deliveries
- Toolmakers, die shops and cutting tool manufacturers
- Heat‑treatment and metallurgical laboratories (testing and hardness verification)
- Design and manufacturing engineers specifying materials for tooling
- Procurement and quality assurance teams requiring conformance documentation
Related standards
Keywords: EN ISO 4957:2018, tool steels, cold‑work, hot‑work, high‑speed tool steels, heat treatment, surface finish, chemical composition, inspection and testing.
