Overview
ISO 10673:2009 defines the characteristics of plain steel washers (product grade A) for metric screw-and-washer assemblies. It covers three washer series - small (S), normal (N) and large (L) - providing standardized dimensions, material and hardness guidance to ensure interchangeability and reliable assembly with metric fasteners in accordance with ISO 10644.
Key topics and technical requirements
- Classification: Types S (small), N (normal) and L (large) for different head styles and applications.
- Dimensions: Clearance hole, outside diameter and thickness specified for nominal thread sizes (examples in the standard cover M2 to M12). Dimensional tables and figures give nominal, minimum and maximum values for each series.
- Material & finish: Plain steel washers in natural finish, or other materials/finishes when agreed between screw manufacturer and washer supplier. Workmanship requirements: uniform quality, free from detrimental defects or burrs.
- Hardness classes: Hardness classes 200 HV and 300 HV are referenced, with allowable hardness ranges after assembly/heat treatment as defined in ISO 10644. Hardness testing to be performed per ISO 6507-1 (Vickers hardness test); test forces depend on nominal thickness (HV2, HV10, HV30 as specified).
- Manufacturing/assembly methods: The standard accommodates washers manufactured and/or assembled either before or after screw heat treatment (methods referenced to ISO 10644 - method 1 and method 2).
- Tolerances & acceptance: General tolerances and acceptance inspection refer to ISO 4759-3 (tolerances for plain washers) and ISO 3269 (acceptance inspection). Note: product grade A does not apply to tolerances of the clearance hole and thickness unless otherwise specified.
- Designation examples: Standardized naming (e.g., Washer ISO 10673‑N‑8‑200 HV WH) to ensure clear procurement and specification.
Applications and users
ISO 10673:2009 is used by:
- Fastener manufacturers and washer suppliers for production and quality control.
- Product designers and mechanical engineers specifying fastener assemblies for machinery, automotive, aerospace and general industrial equipment.
- Purchasing and procurement teams to specify standardized washers for supply contracts.
- Quality inspectors and test laboratories performing dimensional and hardness verification.
- Maintenance and assembly operations that require consistent, interchangeable washer components.
Practical benefits include improved interchangeability, predictable mechanical behavior of screw-and-washer assemblies, and clearer supplier/manufacturer communication.
Related standards
- ISO 10644 - Screw and washer assemblies made of steel (washer hardness classes)
- ISO 4759-3 - Tolerances for plain washers (product grades A and C)
- ISO 6507-1 - Vickers hardness test (test method)
- ISO 3269 - Fasteners - Acceptance inspection
Keywords: ISO 10673:2009, plain washers, product grade A, metric screw and washer assemblies, washer dimensions, hardness 200 HV, hardness 300 HV, ISO 10644.
Open preview (PDF)Plain washers for screw and washer assemblies — Small, normal and large series — Product grade A