UNI EN 14399-9:2018

This European Standard specifies, together with EN 14399-1 and EN 14399-2, the requirements for direct tension indicators, nut face washers (HN) and bolt face washers (HB) as part of high-strength structural bolting assemblies suitable for preloaded joints. These direct tension indicators are specified as part of high-strength structural bolting assemblies of system HR or HV in accordance with EN 14399-3, EN 14399-4, EN 14399-7 or EN 14399-8, with nominal thread sizes M12 up to and including M36 and property classes 8.8/8 or 8.8/10 and 10.9/10. It specifies two property designations H8 and H10 for direct tension indicators, together with general dimensions, tolerances, materials and functional property/ies. Bolting assemblies in accordance with 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 system HR in accordance with EN 14399-3 or EN 14399-7, or by plastic deformation of the engaged threads for system HV in accordance with EN 14399-4 or EN 14399-8. Bolting assemblies conforming to this document may include washer(s) according to EN 14399-6 or to EN 14399-5 (under the nut only).