Overview - ISO 4017:2022 (Hexagon head screws, product grades A and B)
ISO 4017:2022 defines the characteristics and dimensions of hexagon head screws (fully threaded) made of steel and stainless steel, with metric coarse‑pitch threads from M1.6 to M64, and classified into product grades A and B. This sixth edition (2022) updates dimensional tables, restores standard length rules, adds sizes (e.g. M7) and expands accepted property classes and stainless‑steel grades. The standard is intended for specification, manufacturing, inspection and labelling of these fasteners.
Key topics and technical requirements
- Scope and sizes: Metric coarse pitch threads M1.6–M64; product grades A (typical tolerance/finish) and B (alternative dimensional options for large sizes or special lengths).
- Dimensions and tolerances: Detailed head, thread and length dimensions are provided (see Clause 4 and Tables/Annex A). Thread tolerance class and general thread data reference ISO 965‑1 and ISO 225.
- Material and property classes: Steel property classes (e.g. 4.8, 5.6, 8.8, 10.9, 12.9/12.9) and stainless‑steel grades (A2/A4, D4/D6 variants and property class 80 etc.) are specified or selected in conjunction with ISO 898‑1 and ISO 3506‑1.
- Surface condition and coatings: Uncoated, electroplated (ISO 4042), zinc‑flake (ISO 10683), hot‑dip galvanizing (ISO 10684) and passivation options - with coating impacts on tolerances noted.
- Inspection and acceptability: Acceptance inspection aligns with ISO 3269; surface discontinuity limits referenced in ISO 6157 series.
- Marking and labelling: Product marking and package labelling follow ISO 898‑1 (steel) or ISO 3506‑1 (stainless steel) and must include reference to ISO 4017, thread size, nominal length and property symbol.
Practical applications
ISO 4017 is used to:
- Specify and procure standardized hexagon head screws for mechanical assemblies, equipment manufacturing, automotive components, construction and marine fittings.
- Ensure interchangeability and consistent fit/tolerance when replacing or sourcing fasteners globally.
- Guide quality control, incoming inspection and supplier acceptance criteria for fasteners.
Who uses this standard
- Fastener manufacturers and designers
- Mechanical and structural engineers
- Procurement and quality assurance teams
- Test labs and conformity assessors
- Distributors and OEM supply chain managers
Related standards (commonly referenced)
Keywords: ISO 4017, hexagon head screws, metric coarse pitch threads, product grades A and B, fasteners, dimensions, property classes, stainless steel, marking and labelling.
