Overview
ISO 8675:2023 - Fasteners - Hexagon thin nuts (style 0), with fine pitch thread defines the characteristics, dimensions and supply requirements for hexagon thin nuts (style 0) in steel and stainless steel with metric fine pitch threads from 8 mm to 64 mm. The standard covers product grades A and B, specifies dimensional tables, marking and labelling, designation rules, and references related mechanical and acceptance requirements. It also contains a normative Annex A addressing nuts with D > 39 mm (mechanical properties and dimensions).
Key topics and requirements
- Scope and sizes: Fine-pitch hexagon thin nuts, thread sizes M8 to M64 (8 mm–64 mm). Thin nuts used as jam nuts must be assembled with a regular or high nut.
- Design note / warning: Thin nuts have reduced loadability compared to regular/high nuts and are not designed to provide resistance to thread stripping (see ISO 898-2).
- Dimensions and tolerances: Dimensional drawings and tables for 8–39 mm and an Annex A for D > 39 mm. Thread tolerance class 6H and thread tolerances per ISO 965-1.
- Materials and product grades: Steel and stainless steel options; product grade A (typically smaller sizes) and grade B (larger sizes). Stainless-steel grades and property classes can be selected from ISO 3506-2.
- Mechanical properties: Mechanical requirements referenced to ISO 898-2 (steel) and ISO 3506-2 (stainless steel). Annex A provides mechanical properties (including proof-load data) for sizes not covered in those standards.
- Surface condition and coatings: As processed (uncoated) or specified coatings per ISO 4042 (electroplated) and ISO 10683 (zinc flake). Surface discontinuities per ISO 6157-2.
- Marking & labelling: Product marking per ISO 898-2 / ISO 3506-2 and package labelling must include reference to ISO 8675, thread size D×P, material/property class, finish, manufacturer, lot number and quantity.
- Designation examples:
- Hexagon thin nut ISO 8675 – M12×1,5 – 05 (steel, product grade A)
- Hexagon thin nut ISO 8675 – M20×2 – A2-035 (stainless steel, product grade B)
Applications
- Use where a reduced-height nut is required (space-limited assemblies), or as a jam nut paired with a regular/high nut.
- Common in mechanical assemblies that require fine pitch threads and controlled nut geometry for clamping or locking purposes.
Who should use this standard
- Fastener manufacturers and suppliers specifying production dimensions and marking
- Design and mechanical engineers specifying nuts for assemblies
- Quality inspectors, procurement professionals and maintenance engineers verifying conformity and labelling
Related standards