Overview
EN ISO 4018:2022 - Fasteners - Hexagon head screws - Product grade C (ISO 4018:2022) is a CEN-endorsed international standard that defines the characteristics, dimensions and requirements for steel hexagon head screws with metric coarse pitch threads M5 to M64, specified as product grade C. The document harmonizes dimensional tables, marking and labelling rules, and references related mechanical and coating specifications for consistent manufacture, inspection and procurement across Europe and internationally.
Key Topics
- Scope and range: Applies to steel hexagon head screws, metric coarse threads M5–M64, product grade C.
- Dimensions and tolerances: Detailed dimensional tables (M5–M64) and figures for head, thread and underhead geometry; rules for incomplete thread (u ≤ 2P), optional washer-face and indentation.
- Length rules: Defines shortest and greatest standard lengths; greatest standard length limited to 200 mm unless agreed otherwise.
- Head forms and indentation: Permissible free-formed head shapes and optional head indentations added in this edition.
- Marking and labelling: Clause 6 sets requirements for product marking and packaging labelling to ensure traceability and conformity.
- Referenced standards & requirements: Integrates requirements from related ISO documents (e.g., ISO 898-1 for property classes, ISO 888/ISO 4753 for dimensional options, ISO 225, ISO 965-1, ISO 3269, ISO 4042, ISO 6157-1, ISO 10683, ISO 10684).
- Edition changes: Fifth edition updates include addition of M7, restructured tables, tolerance adjustments for M5 head bearing surface, and new marking/labelling rules.
Applications
- Manufacturers: Design and produce consistent, compliant hexagon head screws for inventory and OEM supply.
- Engineers and designers: Specify appropriate fasteners (size, length, property class options) for mechanical assemblies, machinery, automotive, construction and general engineering.
- Purchasing and quality: Use the standard for procurement specifications, acceptance inspection and traceability of supplied fasteners.
- Testing and conformity: Laboratories and inspection bodies apply referenced testing and surface-coating standards for acceptance.
Related Standards (if applicable)
EN ISO 4018:2022 is essential for anyone specifying, manufacturing or inspecting metric hexagon head screws to ensure interchangeability, safety and supply-chain clarity.