Scope and Technical Regulations
This regulatory documentation establishes unified requirements for the geometric parameters and dimensional characteristics of metric fasteners certified by the American National Standard for products ranging from M12 to M36. The list of regulated products includes:
- Heavy metric hex bolts: ASTM A 325 and ASTM A 490.
- Heavy metric hex nuts: ASTM A 563.
- Hardened metric washers (plain and beveled): ASTM F436.
- Compressible-washer-type direct tension indicators: ASTM F 959.
The technological capabilities of EV Group China allow for the supply of this range of fasteners. To clarify stock availability and the possibility of manufacturing custom batches, we recommend sending inquiries to our technical specialists.
Parameters and Tolerances
All linear dimensions in the standard are provided in millimeters. The specified values correspond to the characteristics of products without protective coatings. If anti-corrosion coatings or special heat treatment are required, tolerances for the finished product must be pre-agreed with the customer. The geometric characteristics of the fasteners comply with ASME Y14.5 standards.
Technological Features and Terminology
Production tolerances and the choice of manufacturing method remain at the discretion of the EV Group China engineering department, unless otherwise specified in the client’s technical requirements. Definitions of terminology regarding the structural elements of fastener assemblies are regulated by the ASME B18.12 standard.
Comparison with International Standards (ISO and CEN)
To ensure interchangeability during design, the following correspondences should be considered:
| Product | ISO Standard | CEN Standard |
|---|---|---|
| Nuts | ISO 4775 | CEN 14399 |
| Structural washers | ISO 7415 | CEN 14399 |
| Indicator washers | Not regulated | CEN 14399 |
The CEN 14399 standard is a comprehensive document for structural fasteners, covering a wide range of connection elements.
Normative References
All standards mentioned in the text imply the use of their current editions at the time of manufacturing by EV Group China.