ISO 1083:2018

Overview - What ISO 1083:2018 covers

ISO 1083:2018 defines the classification and grade requirements for spheroidal graphite cast irons (also known as ductile or nodular iron). The standard classifies grades by mechanical properties measured on machined test pieces prepared from cast samples and provides an informative hardness-based classification. It covers two main groups:

• Ferritic to pearlitic spheroidal graphite cast irons (matrix containing ferrite, pearlite, or both)
• Solid-solution strengthened ferritic spheroidal graphite cast irons (ferritic matrix strengthened by increased silicon)

The document specifies sampling routes, test-piece preparation, and reference test methods, and excludes certain specialized irons (pipes/fittings per ISO 2531/ISO 7186, austenitic SG iron per ISO 2892, and ausferritic cast irons per ISO 17804).

Key technical topics and requirements

• Grade designation and order information - how to specify material grades and relevant ordering data.
• Mechanical-property-based classification - grades defined by tensile, elongation and other mechanical measurements taken from machined test pieces.
• Sampling methods - permitted representative sample types: separately cast samples, side-by-side cast samples, cast-on samples, and samples cut from production castings.
• Manufacture and test-piece preparation - requirements for producing cast samples and machining test specimens.
• Testing and normative references - links to standard test methods such as:
  • ISO 6892-1 (tensile testing)
  • ISO 148-1 (Charpy impact)
  • ISO 6506-1 (Brinell hardness)
  • ISO 945-1 (graphite classification)
• Graphite and matrix structure requirements - nodularity, matrix phase expectations and examination procedures.
• Informative annexes - additional guidance on hardness classification, nodularity, fracture mechanics, sampling sectioning and property guidance for castings.

Practical applications and users

ISO 1083:2018 is used by:

• Foundries and metallurgists for production control and material grading of ductile iron castings.
• Quality and inspection engineers to establish sampling plans and acceptance criteria.
• Design and mechanical engineers specifying material grades for components where ductility, strength and hardness matter (including some pressure applications).
• Procurement and standards teams to write clear purchase specifications and ensure traceable compliance.
• Testing laboratories implementing tensile, impact and hardness testing on representative cast samples.

Related standards

• ISO 2531, ISO 7186 (pipe/fittings exclusions)
• ISO 2892 (austenitic spheroidal cast irons)
• ISO 17804 (ausferritic cast irons)
• ISO 6892-1, ISO 148-1, ISO 6506-1, ISO 945-1 (test methods and microstructure)

For implementation, consult the full ISO 1083:2018 document from ISO or your national standards body for precise procedural and numerical requirements.