This document specifies, together with EN 14399-1, the requirements for assemblies of high-strength structural bolts and nuts of system HR suitable for preloaded joints with large widths across flats, thread sizes M12 to M36 and property classes 8.8/8 and 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 elongation of the bolt. For this purpose the components have the following characteristics:
-- nut height according to style 1 (see EN ISO 4032)
-- thread length of the bolt according to ISO 888
Bolt and nut assemblies 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.
1) fub is the nominal tensile strength (Rm) and As the stress area of the bolt.