Overview
EN ISO 7380-1:2023 - Fasteners: Button head screws with reduced loadability - Part 1 covers hexagon socket button head screws (ISO 7380-1:2022) manufactured in steel and stainless steel, with metric coarse pitch threads M3 to M16 and product grade A. The standard defines dimensional, material and marking requirements for button head screws whose head design (head dimensions and socket penetration) reduces loadability compared with conventional fasteners.
Key Topics
- Scope and materials: Applies to steel and stainless-steel hexagon socket button head screws, M3–M16, product grade A. Stainless grades may be selected from ISO 3506-1 where different requirements are requested.
- Reduced loadability: Specifies that loadability in the head is assumed to be 80% of the thread loadability for all sizes and property classes. Reduced ultimate tensile load is indicated by a property class preceded by a zero on the marking.
- Dimensions and geometry: Detailed head, socket and thread dimensions (including socket depth t, wall thickness w, head diameters, underhead radii and reference datum) and limits are given to ensure consistent manufacture and gauge testing.
- Thread and length requirements: Metric coarse pitches M3–M16; reference thread length and shank considerations (reference thread length b updated - including an increase to 3d for certain tests) are specified to support tensile testing and acceptance inspection.
- Marking and labelling: Requirements for marking on the product and labelling on packages are included to support traceability and conformity.
- Normative references: Integrates related fastener standards such as ISO 225, ISO 888, ISO 898‑1, ISO 3506‑1, ISO 4753 and ISO 4759‑1 for tolerances, materials and testing.
Applications
EN ISO 7380-1:2023 is used by:
- Fastener manufacturers - to design and produce hexagon socket button head screws that meet European/ISO dimensional and marking requirements.
- Design and mechanical engineers - to select appropriate button head screws when reduced head loadability, compact head form or aesthetic flush appearance is required.
- Quality and inspection teams - for acceptance inspection, tensile testing and verification against specified dimensions and property-class marking.
- Procurement and standards compliance staff - to specify correct product grade, material and marking in purchase documents.
Common application areas include mechanical assemblies, equipment manufacturing, consumer products and maintenance tasks where a low-profile, rounded button head with an internal hex drive is desired but reduced head loadability must be accounted for.
Related standards
Keywords: EN ISO 7380-1:2023, hexagon socket button head screws, button head screws with reduced loadability, M3–M16, fasteners standard, product grade A, ISO 3506-1.