Technical requirements for bolt connection components according to the ASTM A394 standard
This technical regulation establishes industry standards for the production and incoming inspection of fasteners used in the construction of transmission line towers, distribution substations, and other load-bearing steel structures. Products supplied by EV Group China fully comply with ASTM A394 requirements regarding steel chemical composition, heat treatment, and protective anti-corrosion coating.
Classification of fasteners according to ASTM A394
The standard regulates physical and mechanical parameters as well as marking designations for the following categories of bolt connections:
- Type 0: Bolts made of low- and medium-carbon steels, subjected to hot-dip galvanizing to provide protection against atmospheric corrosion.
- Type 1: High-strength bolts made of medium-carbon steel, subjected to quenching and tempering, followed by hot-dip galvanizing.
- Type 3: Fasteners made of weathering alloy steels, subjected to heat treatment (quenching + tempering) for operation in aggressive environments without additional coating.
Additional components and tolerances
Appendix A1 of the ASTM A394 standard contains specifications for specialized fasteners, including ladder bolts, step bolts, and elements for mounting support equipment, protected by the hot-dip galvanizing method. EV Group China specialists point out that nuts and washers supplied with these bolts must meet the standards of section 4.4 of this standard.
It is important to note that all geometric parameters and dimensional characteristics of hardware in ASTM A394 specifications are given exclusively in the imperial system. When designing and ordering components from EV Group China, it is necessary to use the original imperial values to ensure full compatibility of structural assemblies.