ISO 683-3:2022

Overview

ISO 683-3:2022, "Heat-treatable steels, alloy steels and free-cutting steels - Part 3: Case-hardening steels," specifies the technical delivery requirements for a range of product forms manufactured from case-hardening non-alloy and alloy steels. The standard covers semi-finished products (blooms, billets, slabs), bars, wire rod, finished flat products and hammer/drop forgings supplied in defined heat‑treatment and surface conditions. These steels are generally intended for the manufacture of case‑hardened machine parts.

Key topics and technical requirements

ISO 683-3:2022 defines requirements and processes critical for consistent quality of case-hardening steels, including:

• Scope of supply: product forms and the specific steel grades listed in Table 3 (as referenced in the standard).
• Heat‑treatment and surface conditions: delivery conditions and options identified in Table 1 and Table 2.
• Chemical composition and classification: steel grade designations and classification in accordance with ISO 4948 series and ISO/TS 4949.
• Mechanical properties: hardness and hardenability verification (e.g., Jominy/end‑quench references like ISO 642), plus grain size and inclusion limits.
• Manufacturing and traceability: deoxidation practice, heat‑treatment control and cast traceability requirements.
• Inspection and testing: sampling, chemical analysis, hardness and hardenability tests, inspection documents and test report types per ISO 10474.
• Surface condition, dimensions and tolerances: delivery surface quality (see ISO 7788, ISO 9443) and dimensional requirements.
• Documentation and marking: required purchaser information, ordering details and marking rules to ensure conformity.

(Note: specific composition values and table entries are given in the full standard.)

Applications

ISO 683-3:2022 is used wherever consistent, specified case-hardening steels are required for parts that benefit from a hard wear-resistant surface and a tough core. Typical applications include:

• manufacturing of case‑hardened machine components and power‑transmission parts;
• procurement specifications for suppliers of bars, wire rod, flat products, forgings and semi‑finished steels;
• quality control and inspection planning in steel mills and heat‑treatment shops.

Who should use this standard?

• Steel producers and mills supplying case-hardening grades
• Heat-treatment and forging shops specifying delivery conditions
• Design and procurement engineers preparing material specifications
• Quality, inspection and testing laboratories ensuring conformity to delivery requirements

Related standards

ISO 683-3 references and aligns with other ISO documents for sampling, testing and classification, for example:

• ISO 377 (sampling for mechanical testing)
• ISO 642 (hardenability / Jominy test)
• ISO 10474 (inspection documents)
• ISO 4948 / ISO/TS 4949 (steel classification and naming)

For full technical details, steel producers, purchasers and quality teams should consult the complete ISO 683-3:2022 document.