EN 14399-4 standard, part of a high-strength bolt set Hex head bolts and heavy-duty nuts includes. This set is used in structural steel constructions requiring high preloading and is typically used with HV washers compliant with the EN 14399-6 standard.
EN 14399-4, DIN 6914 (screw) and DIN 6915 (nut) replaces the standards and defines connection elements with a high strength class harmonized across Europe. These sets are particularly steel bridges, crane installations, power plants, and industrial steel structures Developed to provide secure and vibration-resistant connections.
| Feature | |
| Standard | EN 14399-4 |
| Material | Carbon Steel, Alloy Steel |
| Type | Hex Head Bolt + Nut |
| Quality | 10.9 HV |
| Coating | Electrogalvanized (White/Yellow), Hot-Dip Galvanized (HDG), Nickel, Black Oxide, Geomet |
| Tooth Type | Metric (Coarse) – UNC / UNF (optional) |
| Measurement Range | From M12 to M64, 1/2″-2 1/2″ |
| Production Method | Hot forging |
| Thread Direction | Right-Hand Thread (standard) / Left-Hand Thread (upon request) |
- Steel bridge and viaduct systems
- Heavy industrial steel structures
- Power plant installations
- Crane and carrier system connections
- Refinery steel carriers
- Railway superstructure systems
- All steel structures requiring high preload
- ISO 9001:2015 Quality Management System
- ISO 14001:2015 Environmental Management System
- ISO 45001:2018 Occupational Health and Safety Management System
- EU Declaration of Conformity (PED) certificate (Compliance with the Pressure Equipment Directive)
- Our production processes, DIN, EN, ISO, and ASTM is fully compliant with the standards
- Upon request EN 10204 3.1 certificate is provided



This standard, HV type high-strength preloaded used for connections bolt and nut set includes. The pulley is defined under EN 14399-5 and EN 14399-6.
This means that the entire length of the screw has been threaded. This ensures maximum grip even at short connection distances.
Generally, DIN 934 hex nuts, DIN 985 fiber nuts, or heavy-duty DIN 6915 nuts are used according to project specifications.