EN 14399-10 is one of the most important European standards governing HRC (High-Strength Structural Bolting Assemblies with Tension Control) systems, widely used in bridges, steel buildings, wind towers, and heavy industrial structures. As modern steel structures continue to grow in scale and complexity, reliable preloaded bolted connections have become essential for ensuring structural safety and long-term performance. EN 14399-10 is a European standard that specifies the requirements for High-Strength Structural Bolting Assemblies (HRC System) used in preloaded structural steel connections. It is part of the EN 14399 series, which defines the design, manufacturing, testing, and performance requirements for high-strength bolting assemblies used in steel construction across Europe.
The standard covers bolt assemblies consisting of a bolt, nut, and washers that are designed to achieve a controlled preload during installation. EN 14399-10 specifically applies to the HRC (High-Resistance Controlled) system, also known as the tension control bolting system, where the bolt features a splined end that twists off when the specified preload is reached.
Unlike conventional torque-tightened bolts, the HRC system simplifies installation by using a dedicated shear wrench, reducing the influence of operator technique and helping to achieve a more consistent preload in structural connections.
What is EN 14399-10 Standard?
EN 14399-10 is a European standard that specifies the technical requirements for High-Strength Structural Bolting Assemblies (HRC System) used in preloaded structural steel connections. It is part of the EN 14399 series of standards, which governs high-strength bolting systems for steel construction throughout Europe.
Unlike conventional structural bolts, EN 14399-10 HRC bolts feature a splined end that is twisted off during installation using a specialized tension control (shear) wrench. This design allows the required preload to be achieved accurately and consistently, helping to improve installation efficiency while reducing the risk of incorrect tightening.
EN 14399-10 bolt assemblies are typically manufactured in Property Class 10.9 and are supplied as a complete assembly consisting of a bolt, heavy hex nut, and two washers. They are designed for use in preloaded connections in accordance with Eurocode 3 (EN 1993-1-8), making them suitable for safety-critical steel structures.
Key Features of EN 14399-10:
- High-strength structural bolting assembly (HRC system)
- Property Class 10.9 for superior mechanical performance
- Controlled preload achieved through a splined-end tension control system
- Fast and reliable installation using a dedicated shear wrench
- Available in Large Hex Head and Cup Head designs
- Suitable for steel structures requiring high fatigue resistance and secure bolted connections
EN 14399-10 HRC Bolt Types
EN 14399-10 specifies High-Strength Structural Bolting Assemblies (HRC System) designed for preloaded steel connections. Depending on project requirements and regional practices, HRC bolts are commonly available in two head styles: Large Hex Head and Cup Head. Both types are manufactured with a splined end, allowing controlled preload installation using a dedicated shear wrench.
1. Large Hex Head HRC Bolt
The Large Hex Head HRC Bolt is the most widely used type in Europe and international steel construction projects. It features a heavy hexagonal head that provides excellent load distribution and is designed for high-strength structural connections.
2. Cup Head HRC Bolt
The Cup Head HRC Bolt features a smooth, rounded head with an integrated splined end. It provides the same preload performance as the Large Hex Head version while meeting specific project or regional design requirements.
YOKELINK China supplies complete EN14399-10 structural bolting assemblies including:
- Large Hex Head
- Cup Head
- Grade 10.9
- HDG
- OEM
- Custom sizes
Why EN 14399-10 Matters
Preloaded bolted connections play a critical role in maintaining the strength, stability, and long-term performance of steel structures. By providing a calibrated preload through its tension control installation method, EN 14399-10 helps ensure consistent clamping force, minimizes installation errors, and enhances the safety and durability of structural connections.
EN14399-10 has become one of the most widely recognized standards for high-strength preloaded structural bolting systems. Whether used in bridges, steel buildings, wind energy, or industrial facilities, HRC structural bolts provide reliable preload, efficient installation, and long-term structural performance.
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