Overview
ISO 12474:2010 - "Hexagon socket head cap screws with metric fine pitch thread" specifies the characteristics of hexagon socket head cap screws with metric fine pitch threads for nominal thread diameters d = 8 mm to 36 mm and product grade A. The standard provides dimensional data, acceptance guidance and cross-references to mechanical property, thread and surface-treatment standards. It also includes an informative annex with approximate masses for commercially available lengths.
Key topics and requirements
- Scope and sizes: Covers hexagon socket head cap screws with fine pitch metric threads from M8 to M36, product grade A.
- Dimensions and geometries: Detailed head, socket and shank dimensions (figures and Table 1) including permissible socket forms, head edges and underhead fillets.
- Threading and tolerances: Refers to ISO thread standards (ISO 261, ISO 965‑2, ISO 965‑3) and tolerance classes (e.g., 5g/6g depending on property class).
- Mechanical properties and materials: Links to ISO 898‑1 for carbon/alloy steels, ISO 3506‑1 for stainless steels and ISO 8839 for non‑ferrous metals; property classes such as 8.8, 10.9, 12.9 are used.
- Surface finish and coatings: Requirements for electroplated finishes (ISO 4042) and zinc‑flake coatings (ISO 10683) are referenced.
- Quality and acceptability: Surface discontinuity limits referenced (ISO 6157 series) and acceptance inspection procedures (ISO 3269).
- Designation and mass data: Provides a sample designation format (e.g., Hexagon socket head cap screw ISO 12474 - M12 × 1.5 × 80 - 12.9) and Annex A lists approximate masses for procurement/weighting purposes.
Applications and who uses it
ISO 12474 is intended for:
- Design engineers specifying fine‑pitch hexagon socket cap screws where precise dimensions and interchangeability matter.
- Manufacturers and fastener suppliers who produce, mark and sell metric fine‑pitch socket cap screws.
- Procurement and quality assurance teams using the standard for purchasing specifications, acceptance inspection and conformance checks.
- Maintenance and assembly operations that require consistent fastener geometry, thread fit and mechanical performance.
Typical practical uses include specifying fasteners for machine assemblies, precision equipment and applications where fine pitch threads are needed for finer adjustment or higher clamp accuracy.
Related standards
ISO 12474 references and complements:
Keywords: ISO 12474, hexagon socket head cap screws, metric fine pitch thread, M8–M36, product grade A, fastener dimensions, tolerance, ISO standards.
