Overview
EN ISO 10673:2009 - Plain washers for screw and washer assemblies (Product grade A) is the CEN-adopted version of ISO 10673:2009. The standard specifies the characteristics of plain steel washers (small, normal and large series) used with metric screw and washer assemblies in accordance with ISO 10644. It covers classification, dimensions, material and hardness options, tolerances, workmanship and designation rules for washers intended for combined screw-and-washer products.
Key topics and requirements
- Scope and classification
- Defines three washer series: Type S (small), Type N (normal) and Type L (large) - selected depending on screw head type and application.
- Dimensions
- Provides detailed dimensional tables and figures for nominal thread sizes (commonly M2 to M12), including clearance hole, outside diameter and thickness for types S, N and L.
- Material and hardness
- Washers are plain steel; hardness classes are specified (typically 200 HV and 300 HV) and hardness testing follows ISO 6507-1 (Vickers).
- Washers may be heat treated (HT) or work hardened (WH); method of manufacture and assembly with the screw follows ISO 10644.
- Tolerances and product grade
- Product grade A tolerances are applied (with some exceptions), and dimensional tolerances reference ISO 4759‑3 for plain washers.
- Finish, workmanship and acceptability
- Washers are supplied in a plain (natural) finish unless otherwise agreed; parts must be free of burrs and defects.
- Acceptance inspection follows ISO 3269.
- Designation
- Clear designation format examples are provided (e.g., Washer ISO 10673‑N‑8‑200 HV HT), useful for procurement and specification.
Applications and who uses it
- Design engineers and OEMs specifying screw-and-washer assemblies for machinery, automotive, electronics and general mechanical assemblies.
- Fastener and washer manufacturers producing metric plain washers to standardized dimensions and hardness classes.
- Purchasing, quality assurance and laboratory teams who perform inspection, hardness testing and acceptance checks.
- Assemblers and contract manufacturers integrating washers with screws where controlled mechanical properties and interchangeability are required.
Related standards
- ISO 10644 - Screw and washer assemblies (washer hardness classes / assembly methods)
- ISO 4759‑3 - Tolerances for plain washers (product grades)
- ISO 3269 - Fasteners - Acceptance inspection
- ISO 6507‑1 - Vickers hardness test (test method)
EN ISO 10673:2009 ensures interchangeability, mechanical performance and consistent quality for plain washers used in metric screw-and-washer assemblies - critical for reliable fastening and standardized supply chains.