BS EN 14399-7:2018

What is BS EN 14399‑7 - Countersunk head bolt and nut assemblies about?  

BS EN 14399 is a series of European standards on bolting assemblies that discusses the best procedures and specifications required for manufacturing high-quality countersunk head bolt and nut assemblies. BS EN 14399‑7 is the seventh part of a series of documents on High-strength structural bolting assemblies for preloading.

BS EN 14399‑7 specifies, together with EN 14399-1 and EN 14399-2, the requirements for assemblies of high-strength structural countersunk bolts and nuts of system HR suitable for preloaded joints with thread sizes M12 to M36 and property classes 8.8/8 or 8.8/10 and 10.9/10. Bolting assemblies by this document have been designed to allow preloading of at least 0,7 fub × As1) according to EN 1993-1-8 (Eurocode 3) and to obtain ductility predominantly by plastic elongation of the bolt. For this purpose the components have the following characteristics: 

• Regular nut height according to style 1, see EN ISO 4032; 
• Thread length of the bolt according to ISO 888. 

Bolting assemblies by BS EN 14399‑7 include washers according to EN 14399-6 or EN 14399-5. 

General requirements and requirements for suitability for preloading are specified in EN 14399-2. Clamp lengths and grip lengths for the bolting assemblies are specified in the normative Annex A. 

NOTE: Attention is drawn to the importance of ensuring that bolting assemblies are correctly used if satisfactory results are to be obtained. For recommendations concerning the proper application, reference to EN 1090-2 is made. 

Who is BS EN 14399‑7 - Countersunk head bolt and nut assemblies for?  

BS EN 14399‑7 on the countersunk head bolt and nut assemblies is relevant to: 

• Manufacturer of the countersunk head bolt and nut assemblies  

Why should you use BS EN 14399‑7 - Countersunk head bolt and nut assemblies? 

Head bolts are the connecting elements between the engine block, cylinder head gasket, and cylinder head. A nut is a type of fastener with a threaded hole. Nuts are almost always used in conjunction with a mating bolt to fasten multiple parts together. 

BS EN 14399‑7 navigates you through the dimensions of bolts, specification for bolts and reference standard, marking of bolts, dimensions of nuts, specification for nuts and reference standards, proof load values of nuts. 

BS EN 14399‑7 provide guidance on functional characteristics of the bolt/nut/washer assembly. BS EN 14399‑7 exemplifies the required composition of high-strength structural bolting assemblies and component marking that help you achieve precision in terms of product functionality. BS EN 14399‑7 provides dimensions of bolts and nuts which helps you to manufacture bolts and nuts of precise dimension.

As a user of BS EN 14399‑7, you can be ensured of the properties of the head bolt and nut assemblies. With obedience and compliance to BS EN 14399‑7, you can efficiently manufacture high-quality countersunk head bolt and nut assemblies. BS EN 14399‑7 provides you with comprehensive information useful throughout the process of production.

What’s changed since the last update?  

BS EN 14399‑7:2018 supersedes BS EN 14399‑7:2007, which is withdrawn. 

In comparison with EN 14399-7:2007, the following modifications have been made: 

• Table 1 contains the overview of the composition of bolting assemblies and component marking has been revised 
• The coefficient of variation of the k-factor, Vk, was changed from 0,10 to 0,06 
• Specifications for the designation of the bolting assemblies have been revised 
• Annex A with detailed specifications on clamp lengths and grip lengths has been added