EN 14399 Structural Bolt Assembly Manufacturer in India

EN 14399 High-Strength Structural Bolt Assemblies

New Star Industries manufactures and supplies EN 14399 high-strength structural bolt assemblies designed for preloaded steel connections used in heavy structural applications. The EN 14399 standard defines the requirements for assemblies consisting of bolts, nuts, and washers that are engineered to function together as a single fastening system.

According to EN 14399-1, these components must be supplied as a matched assembly so that the bolt, nut, and washer work together effectively when tightened to a specified preload. This controlled preloading ensures reliable structural performance and maintains joint stability even under dynamic loads and vibrations.

The standard emphasizes that the complete assembly must meet the same part of the EN 14399 specification and be tested together to guarantee proper functionality and safety in structural steel connections.

Main Components of EN 14399 Structural Bolt Assemblies

• High-Strength Bolts The bolts used in EN 14399 assemblies are high-strength fasteners with a large hexagonal head and carefully controlled thread length. These bolts are designed to deliver exceptional mechanical performance, typically providing a minimum tensile strength of 1000 MPa and a minimum yield strength of 900 MPa.
• Structural Nuts:Each bolt is paired with a matching high-strength nut designed to meet the required thread compatibility and strength class. These nuts must meet strict requirements for proof load and hardness, ensuring that they can withstand the high preloading forces applied during installation.
• Hardened Washers: Hardened steel washers are an essential part of EN 14399 assemblies. Their role is to protect the connected surfaces during tightening while distributing the clamping force evenly across the joint. The hardness of these washers is carefully controlled to maintain consistent preload and structural reliability.

To ensure proper performance, bolts, nuts, and washers must be supplied by the same manufacturer and tested together as a complete assembly, guaranteeing compatibility and reliable performance under preloading conditions.

Material & Grades

Key Features of EN 14399 Bolting Assemblies

• ✔ Preloaded (Tensioned) – Bolts are tightened to a controlled preload to resist slippage.
• ✔ High-Strength Grades – Typically 8.8 and 10.9 (HV – High Strength).
• ✔ Slip-Resistant Connections – Prevents movement between connected parts under load.
• ✔ HV (High Strength) System – Includes bolt, nut, and hardened washers.
• ✔ Corrosion Protection – Often hot-dip galvanized (HDG) or Dacromet-coated.

EN 14399 Sub-Standards (Different Systems)

EN 14399-2 focuses on the conformity evaluation procedures for EN 14399 assemblies. It defines the testing procedures to verify that a Preloaded Structural bolting assembly (Bolt, Nut, and Washer) for Both HV & HR Series is capable of achieving the specific preload and required Tension.

EN 14399-3 refers to EU standards for HR (High Resistance) bolts with large hexagonal head Bolt assemblies. This standard provides the detailed specifications, dimensions, and performance criteria for the components (bolt, nut, and washers) that form an HR type high-strength structural bolting assembly for preloading.

EN 14399-4 stands for "Hochfest Vorgespannt," which translates to "high-strength preloaded" in German. This indicates that the bolt and nut assembly are designed to be tightened to a specific preload, creating a high-strength connection.

Marking & Identification

• Bolts: Head marked with grade (8.8 or 10.9) and manufacturer ID
• Nuts: Top face marked with grade (8.8 or 10.9)
• Washers: Must be clearly identifiable as hardened

Coatings For Common Corrosion Protection

• Hot-dip galvanized (HDG)
• Geomet® (zinc-flake coating)
• Dacromet

Testing & Compliance

• Bolt/nut: Proof load, hardness, tensile tests (ISO 898-1/2)
• Assembly: Preload verification (turn-of-nut or DTI methods)

Comparison to Other Standards

EN 14399 Structural Bolt Assemblies

New Star Industries is a trusted EN 14399 Structural Bolt Assembly Manufacturer in India, supplying high-strength bolting solutions for critical steel construction projects. These assemblies are specially designed for structural connections that require controlled tightening and high clamping force.

An EN 14399 bolt assembly typically consists of a high-strength bolt, matching nut, and hardened washer that together create a secure and slip-resistant joint. These systems are widely used where structural reliability, load-bearing capability, and long-term durability are essential.

Industries & Applications

EN 14399 structural bolt assemblies are commonly used in infrastructure and heavy engineering applications where strong and dependable connections are required.

• Steel bridge construction and seismic-resistant structures
• High-rise commercial and residential buildings
• Crane rails and heavy industrial machinery installations
• Wind turbine towers and renewable energy projects
• Offshore platforms and marine engineering structures

Overview of BS EN 14399-1

BS EN 14399-1 forms part of the European standards governing high-strength structural bolting assemblies used in steel construction. The standard establishes the fundamental requirements for bolt assemblies that are designed to create preloaded structural connections.

These bolting systems are typically used in slip-resistant joints and other structural applications where the connection must withstand heavy loads, vibration, and dynamic stresses over long periods of operation.

Preload Requirements

A key feature of EN 14399 structural bolts is the requirement for controlled tightening. During installation, the bolts must be tightened to achieve a specified minimum preload (Fp,C), ensuring that the joint maintains adequate clamping force.

The required preload values and tightening procedures are defined in the following standards:

• EN 14399-3 – HR system bolt assemblies
• EN 14399-4 – HV system bolt assemblies

Scope of EN 14399-1

EN 14399-1 outlines the general specifications for high-strength structural bolting assemblies, particularly for heavy-duty structural applications requiring controlled preload.

The standard applies to bolting systems used in major steel construction projects such as bridges, industrial facilities, buildings, and crane structures. It also works in conjunction with other parts of the EN 14399 series, which define the detailed requirements for bolts, nuts, and washers.

These components are covered in additional standards including EN 14399-2 through EN 14399-10, ensuring that each element of the assembly functions together to deliver safe and reliable structural performance.

Reliable Structural Fastening Solutions

High-strength bolting systems compliant with EN 14399 are essential for maintaining the strength, slip resistance, and durability of structural steel connections. Choosing the right bolt, nut, and washer combination from the EN 14399 series ensures that the connection performs reliably even under demanding conditions.

As an experienced EN 14399 Structural Bolt Assembly Manufacturer in India, New Star Industries delivers precision-engineered bolting solutions that meet international quality standards for infrastructure, construction, and heavy engineering projects.