EN 14399-3 Bolts HR System
EN 14399-3 bolts are high-strength structural bolting assemblies designed for preloaded steel connections and form part of the HR system specified by the EN 14399 series. These assemblies are manufactured for demanding structural steelwork applications where reliable preload, strength and controlled performance are required. Available in metric sizes from M12 to M36, EN 14399-3 assemblies are supplied in the applicable bolt and nut property class combinations, including 8.8/8, 8.8/10 and 10.9/10.
The HR system is designed to provide the required ductility primarily through plastic elongation of the bolt during tightening. Complete assemblies consist of compatible hexagon bolts, nuts and washers, with components selected according to the applicable EN 14399 requirements. Uncoated and hot-dip galvanized options can be supplied, while other coating requirements can be considered according to project specifications. EN 14399-3 HR system assemblies are suitable for steel buildings, bridges, infrastructure and other preloaded structural connections.
Specification:
EN 14399-3 HR system bolting assemblies are manufactured according to the dimensional, mechanical and functional requirements of EN 14399-3. The assemblies are available in metric thread sizes from M12 to M36 and are supplied with compatible nuts and washers for preloaded structural connections. Bolt and nut property class combinations include 8.8/8, 8.8/10 and 10.9/10. Dimensions, thread length, nut and washer specifications are controlled according to the applicable EN standards to ensure proper assembly and reliable preload performance.
| Item | Specification |
|---|---|
| Standard | EN14399-3 |
| Product Type | High Strength Structural Bolting Assembly |
| System | HR |
| Size Range | M12-M36 |
| Property Class | ISO898-1 Class8.8,10.9 |
| Thread | Metric Coarse |
| Thread Standard | ISO261,ISO965 |
| Surface Treatment | Uncoated,Hot Dip Galvanized |
| Hdg Standard | ISO10684 |
| Assembly | Bolt+Nut+Washer |
| Application | Preloaded Structural Steel Connection |
| Inspection | Dimensions, Thread,Mechanical Property,Coating |
Dimension Chart of EN 14399-3 Bolts HR System:
EN 14399-3 HR system bolting assemblies are available in metric sizes from M12 to M36. Bolt dimensions, thread lengths and associated component dimensions are specified according to the requirements of EN 14399-3 and the applicable referenced standards. The following chart provides commonly supplied dimensions; detailed dimensions may vary according to the nominal diameter, bolt length and applicable configuration.
| Mon | M12 | M14 | M16 | M18 | M20 | M22 | M24 | M27 | M30 | M36 |
| P | 1.75 | 2 | 2 | 2.5 | 2.5 | 2.5 | 3 | 3 | 3.5 | 4 |
| da max | 15.2 | 17.2 | 19.2 | 21.7 | 24.4 | 26.4 | 28.4 | 32.4 | 35.4 | 42.4 |
| ds max | 12.7 | 14.7 | 16.7 | 18.7 | 20.84 | 22.84 | 24.84 | 27.84 | 30.84 | 37 |
| ds min | 11.3 | 13.3 | 15.3 | 17.3 | 19.16 | 21.16 | 23.16 | 26.16 | 29.16 | 35 |
| e min | 23.91 | 26.17 | 29.56 | 32.95 | 35.03 | 39.55 | 45.2 | 50.85 | 55.37 | 66.44 |
| k max | 7.95 | 9.25 | 10.75 | 12.4 | 13.4 | 14.9 | 15.9 | 17.9 | 19.75 | 23.55 |
| k min | 7.05 | 8.35 | 9.25 | 10.6 | 11.6 | 13.1 | 14.1 | 16.1 | 17.65 | 21.45 |
| r min | 1.2 | 1.2 | 1.2 | 1.5 | 1.5 | 1.5 | 1.5 | 2 | 2 | 2 |
| s max | 22 | 24 | 27 | 30 | 32 | 36 | 41 | 46 | 50 | 60 |
| s min | 21.16 | 23.16 | 26.16 | 29.16 | 31 | 35 | 40 | 45 | 49 | 58.8 |
Application of EN 14399-3 Bolts HR System:
Steel Buildings & Structural Frames
EN 14399-3 HR system bolting assemblies are widely used in structural steel buildings and large steel frames where preloaded connections are required. They provide high-strength connections between beams, columns, braces and other structural members, helping maintain reliable joint performance under demanding loads.
Bridges & Infrastructure
These high-strength structural bolting assemblies are suitable for bridges, steel infrastructure and other large-scale construction projects. The HR system is designed for preloaded connections where controlled bolt tension and reliable structural performance are important for long-term service.
Industrial & Heavy-Duty Structures
EN 14399-3 bolting assemblies can also be used in industrial facilities, power plants, petrochemical structures, heavy equipment support frames and other demanding steel structures. Their high-strength design and controlled preload characteristics make them suitable for connections subjected to significant static and dynamic loads.