ISO 4990:2023

Overview - ISO 4990:2023 (Steel castings - General technical delivery requirements)

ISO 4990:2023 defines the general technical delivery requirements for the supply of steel, nickel and cobalt alloy castings. It covers the information purchasers must provide, foundry manufacturing conditions, requirements for sampling and preparation of test pieces, inspection and testing (both non‑specific and specific), marking for traceability, and complaint handling. The standard also provides a set of supplementary requirements (Annex B) that apply only when individually requested by the purchaser. For investment castings, ISO 16468 applies instead.

Key technical topics and requirements

• Information to be supplied by the purchaser: drawing or pattern identification, material standard/grade, delivery condition, and any supplementary requirements or NDT procedures.
• Foundry practice and cleaning: melting, moulding, heat treatment method selection is normally left to the manufacturer unless otherwise agreed; castings must be cleaned sufficiently for inspection.
• Test blocks and sampling:
  • Test blocks can be cast separately, attached or integrally on castings; minimum test block thickness specified (28 mm minimum unless otherwise agreed).
  • Test pieces must be taken at specified distances from surfaces; sampling and preparation follow ISO 14284 for chemical analysis.
• Mechanical testing:
  • Tensile test: typically one tensile test per test lot, in accordance with ISO 6892‑1.
  • Charpy impact test: when specified, three V‑notch specimens per required temperature (ISO 148‑1); average must meet material specification and at most one value may be as low as 70% of minimum.
  • Retest and heat‑treatment provisions are defined when initial tests fail.
• Chemical composition: heat (cast) analyses required for each ladle if multiple ladles are used; chip sampling requires removal at least 6 mm below surface for sections >15 mm.
• Inspection documents and traceability: inspection certificates must follow ISO 10474, include chemical and mechanical test results and provide traceability; electronic certificates accepted with prior agreement.
• Production welding: permitted unless purchaser specifies otherwise; welding procedures should conform to ISO 11970.
• Supplementary requirements: a range of optional inspections/tests in Annex B are available only if individually specified.

Practical applications and who uses ISO 4990:2023

• Foundries manufacturing steel, nickel or cobalt alloy castings - to set and demonstrate delivery and quality practices.
• Purchasers and procurement teams - to specify contractual delivery, testing and inspection requirements.
• Quality and metallurgical engineers - to define sampling, test-piece preparation, mechanical/chemical test methods and retest procedures.
• Design and manufacturing engineers - to coordinate drawing/pattern requirements, machining allowances and acceptance criteria.
• Third‑party inspectors and certification bodies - to verify conformance and produce inspection documents.

Related standards

• ISO 16468 - Investment castings (when applicable)
• ISO 404 - Steel and steel products - General delivery requirements
• ISO 10474 - Inspection documents for steel products
• ISO 11970 - Welding procedures for production welding of steel castings
• ISO 14284 - Sampling and preparation for chemical analysis
• ISO 6892‑1 (tensile testing) and ISO 148‑1 (Charpy impact testing)

Keywords: ISO 4990:2023, steel castings, technical delivery requirements, inspection and testing, sampling, test blocks, Charpy, tensile test, traceability, foundry practice, supplementary requirements.