Technical Regulations and Scope
The EN ISO 8673 standard defines the geometric parameters and physical-mechanical characteristics of hexagon nuts, style 1, with metric fine pitch thread. The nominal thread diameter range covers values from 8 to 64 mm. For products with a diameter of 8–16 mm, accuracy class A is established, while for the 16–39 mm range, accuracy class B is applied. Products supplied by EV Group China fully comply with these regulatory requirements.
If it is necessary to select specifications not covered by this standard, refer to the following relevant documents: ISO 724, ISO 898-2, and ISO 965-1.
Important note: When using nuts with a fine thread pitch, there is an increased risk of thread stripping due to the reduced profile height. In critical assemblies with high axial loads, EV Group China engineers recommend using high nuts (style 2) according to ISO 8674.
Technical Delivery Conditions and Quality Control
| Manufacturing materials | Steel | Stainless steel | Non-ferrous metals |
| General requirements | According to ISO 8992 | ||
| Thread accuracy class | 6H (according to ISO 724, ISO 965-1) | ||
| Property class | D≤39 mm: 6, 8; D≤16 mm: 10 (per ISO 898-2). D>39 mm: per customer specification. | D≤24 mm: A2-70, A4-70; 24 mm<D≤39 mm: A2-50, A4-50 (per ISO 3506-2). | According to ISO 8839 |
| Tolerances and deviations | D≤16 mm: class A; D>16 mm: class B (per ISO 4759-1) | ||
| Surface quality and coating | Electroplated coating (ISO 4042), non-electrolytic zinc flake coating (ISO 10683). | Passivation according to ISO 16048. | Electroplated coating according to ISO 4042. |
| Additional coating types are subject to agreement with the EV Group China engineering department when placing an order. | |||
| Surface condition | Surface defects are regulated by ISO 6157-2. | – | – |
| Product acceptance | Quality control methods comply with the ISO 3269 standard. | ||