Overview
ISO 10679:2019 - Steels - Cast tool steels specifies accepted tool steel compositions for castings. The second edition updates grade numbering and (where available) lists similar UNS cast grades in Annex A. This standard sets the baseline chemical composition, delivery information, and heat-treatment guidance for cast tool steels used in tooling, dies, molds and wear-resistant components.
Key Topics
- Scope and purpose: Defines chemical composition requirements for a wide range of cast tool-steel grades intended for manufacturing castings.
- Chemical composition (Table 1): Specifies elemental mass-fraction ranges (C, Si, Mn, P, S, Cr, Mo, Ni, V, Co, W) for each ISO grade (examples: GX100CrMoV5-1, G50CrMo12-14, GX83WMoCrV6-5-4-2). These composition limits are mandatory for conformity.
- Heat treatment (Table 2): Provides annealing temperatures and indicative Brinell hardness values for many grades. The standard notes heat treatment shall be agreed between manufacturer and purchaser; annealing data are informational.
- Purchaser information requirements: The purchaser must specify the required grade, delivery heat-treatment condition (including “as-cast” if applicable), Brinell hardness requirements if needed, machined surfaces, and part drawings or solid models.
- Delivery and marking: Materials delivered under ISO 10679 shall conform to the general technical delivery requirements in ISO 4990; marking follows ISO 4990 provisions.
- Supplementary requirements: Optional normative supplementary requirements from ISO 4990 can be applied by agreement between purchaser and manufacturer.
- Annex A (informative): Lists UNS numbers similar to ISO cast grades for cross-referencing; a note clarifies these UNS grades may not be fully equivalent.
Applications and Users
ISO 10679 is used where consistent, specified cast tool-steel compositions are required:
- Tool, die and mold manufacturers needing cast tool-steel materials for forging dies, extrusion tooling, die-casting inserts and wear parts
- Foundries producing cast tool-steel components and specifying composition and heat-treatment options
- Procurement, quality and metallurgical engineers who must verify chemical composition, hardness and delivery conditions
- Design and manufacturing teams requiring standardized grade designation and cross-references to UNS numbers
Related Standards
- ISO 4990 - Steel castings - General technical delivery requirements (normative reference for delivery, marking and supplementary requirements)
- EN 10027-1 / EN 10027-2 - Steel designation systems (referenced by Annex A grade naming)
ISO 10679:2019 helps ensure reliable selection, specification and verification of cast tool steels by standardizing composition ranges, delivery conditions and cross-references to other designation systems - improving quality control and interoperability across foundries and toolmakers.
