This document specifies together with EN 14399-1 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 M 12 to M 36 and property classes 10.9/10.
Bolt and nut assemblies to this document have been designed to allow preloading of at least 0,7 fub × As 1) according to ENV 1993-1-1 (Eurocode 3) and to obtain ductility predominantly by plastic deformation of the engaged threads. For this purpose the components have the following characteristics:
-- nut height approximately 0,8 d
-- bolt with short thread length
Bolt and nut assemblies according to this document include washers according to EN 14399-6 or to EN 14399-5 (under the nut only).
NOTE Attention is drawn to the importance of ensuring that the bolts are correctly used if satisfactory result are to be obtained. For recommendations concerning proper application, reference to ENV 1090-1 is made.
The test method for suitability for preloading is specified in EN 14399-2.
Clamp lengths for the bolt/nut/washer assemblies are given in the normative Annex A.
1) fub is the nominal tensile strength (Rm) and As the stress area of the bolt.