EN 14399-4 Bolts HV System
EN 14399-4 bolts are high-strength structural bolting assemblies of the HV system, designed for preloaded joints in structural steelwork. The assemblies are specified for metric thread sizes from M12 to M36 and property class 10.9/10, and are designed to achieve a preload of at least 0.7 fᵤb × Aₛ in accordance with the applicable structural design requirements. EN 14399-4 assemblies consist of compatible hexagon bolts, nuts and washers and are intended to work as a complete system for reliable preloaded structural connections.
A key characteristic of the HV system is its specific bolt and nut geometry. Compared with the HR system specified in EN 14399-3, HV assemblies use a nut with a height of approximately 0.8d and a bolt with a short thread length. The required ductility is obtained predominantly through plastic deformation of the engaged threads during tightening, rather than primarily through plastic elongation of the bolt. This design makes EN 14399-4 suitable for demanding steel construction applications where correctly matched components and controlled preloading are essential.
Specification:
EN 14399-4 components are manufactured and inspected according to the applicable dimensional, thread, mechanical and surface treatment requirements. Bolt threads are based on ISO metric coarse threads, with thread tolerances specified for the bolt and nut. The mechanical properties of the bolt and nut are referenced to the relevant ISO standards, while compatible washers and other assembly components are selected according to the EN 14399 series. Surface finishes, dimensional tolerances and acceptance requirements are controlled according to the applicable European standards.
| Item | Specification |
|---|---|
| Standard | EN14399-4:2015 |
| General Requirements | EN14399-1/EN14399-2 |
| Product Type | High Strength Structural Bolt |
| System | HV |
| Size Range | M12-M36 |
| Property Class | 10.9 |
| Mechanical Proeperty Standard | ISO898-1 |
| Thread | Metric Coarse |
| Thread Standard | ISO261,ISO965 |
| Surface Treatment | Uncoated,Hot Dip Galvanized |
| Hdg Standard | ISO10684 |
| Inspection | Dimensions, Thread,Mechanical Property,Coating |
Dimension Chart of EN 14399-4 Bolts HV System:
The EN 14399-4 dimension chart provides the key dimensional information for HV system bolts and their associated components. Bolt dimensions are specified according to the nominal diameter and length, including head dimensions, thread length and other relevant geometry. Compatible nuts and washers are manufactured to the corresponding EN 14399 requirements to ensure correct assembly. The standard covers metric sizes from M12 to M36, with detailed dimensions depending on the selected bolt size and length.
| Mon | M12 | M16 | M20 | M22 | M24 | M27 | M30 | M36 |
| P | 1.75 | 2 | 2.5 | 2.5 | 3 | 3 | 3.5 | 4 |
| da max | 15.2 | 19.2 | 24 | 26 | 28 | 32 | 35 | 41 |
| ds max | 12 | 16 | 20 | 22 | 24 | 27 | 30 | 36 |
| ds min | 11.3 | 15.3 | 19.16 | 21.16 | 23.16 | 26.16 | 29.16 | 35 |
| e min | 23.91 | 29.56 | 35.03 | 39.55 | 45.2 | 50.85 | 55.37 | 66.44 |
| k max | 8.45 | 10.75 | 13.9 | 14.9 | 15.9 | 17.9 | 20.05 | 24.05 |
| k min | 7.55 | 9.25 | 12.1 | 13.1 | 14.1 | 16.1 | 17.95 | 21.95 |
| r min | 1.2 | 1.2 | 1.5 | 1.5 | 1.5 | 2 | 2 | 2 |
| s max | 22 | 27 | 32 | 36 | 41 | 46 | 50 | 60 |
| s min | 21.16 | 26.16 | 31 | 35 | 40 | 45 | 49 | 58.8 |
Application of EN 14399-4 Bolts HV System:
Preloaded Structural Steel Connections
EN 14399-4 HV bolting assemblies are designed for preloaded connections between structural steel components. They are suitable for joints where the connection must be tightened to a specified preload and the components need to function together as a matched bolting assembly.
High-Strength Steel-to-Steel Joints
These assemblies are suitable for high-strength connections between steel members such as beams, columns, plates, bracing members and fabricated structural components. They can be used where standardized HV system components are required for reliable structural connections.
Slip-Resistant Structural Joints
EN 14399-4 assemblies are suitable for friction-type structural joints where maintaining the required clamping force is important to the performance of the connection. They can be used in structural applications where joint movement and slip need to be controlled through appropriate design, surface preparation and bolt preload.