BS EN 14399-4:2015

What is BS EN 14399-4 - Structural bolting guidance about?  

Preloaded bolted assemblies are very sensitive to differences in manufacture and lubrication. Therefore, it is important that the bolting assemblies are supplied by one manufacturer who is always responsible for the functionality of the bolting assemblies. 

BS EN 14399-4 on structural bolting reflects the situation in Europe where two technical solutions exist to achieve the necessary ductility of bolt/nut/washer assemblies. These solutions consist of two different systems (HR and HV) of bolt/nut/washer assemblies. Both systems are well proven, and it is the responsibility of the experts using structural bolting whether they use the one or the other system. 

BS EN 14399-4 specifies together with EN 14399-1 and EN 14399-2, the requirements for assemblies of high-strength structural bolts and nuts of system HV suitable for preloaded joints with large widths across flats, thread sizes M12 to M36 and property classes 10.9/10. 

General requirements and requirements for suitability for preloading are specified in EN 14399-2. BS EN 14399-4 specifies clamp lengths and grip lengths for the bolting assemblies. 

Who is BS EN 14399-4 - Structural bolting guidance for? 

BS EN 14399-4 on structural bolting guidance is useful for: 

• Manufacturers of bolting assemblies and components 
• Inspection bodies for the inspection of components and bolting assemblies 
• Quality control personnel 
• Organizations that design, maintain bolting assemblies 
• Testing authorities 
• Design engineers 
• Research and development team 

Why should you use BS EN 14399-4 - Structural bolting guidance?  

With the mechanical properties of the components, also the functionality of the bolting assemblies requires that the specified preload can be achieved if the bolting assemblies are tightened with a suitable procedure. For this purpose, BS EN 14399-4 provides with you a test method for the suitability of the bolting assemblies for preloading, which will demonstrate whether the functionality of the bolting assemblies is fulfilled. 

The performance of the high-strength structural bolting assemblies depends on the properties of their specific components. BS EN 14399-4 assess the essential characteristics listed in EN 14399-1 through the verification of the properties of the components and bolting assemblies, as applicable. 

Following the guidelines provided in BS EN 14399-4 creates a standardized approach for you and you can deliver high-quality bolting assemblies and related components to your customers. These customers will be able to safely use bolts/nuts/washer assemblies. 

What’s changed since the last update?  

BS EN 14399-4:2015 supersedes BS EN 14399-4:2005, which is withdrawn. BS EN 14399-4:2015 includes some technical changes with respect to BS EN 14399-4:2005. These include: 

• The overview of the composition of bolting assemblies and component marking has been added 
• The use of washers in accordance with EN 14399-5 was deleted 
• The coefficient of variation of the k-factor, Vk, has changed from 0,10 to 0,06 
• Specifications for the designation of the bolting assemblies have been revised 
• In Annex A detailed specifications on grip lengths has been added