This document belongs to the suite of European Standards EN 14399 and is designed to be read in conjunction with EN 14399-1 for:- general requirements;- testing for conformity evaluation;- evaluation of conformity;- regulatory marking;for assemblies of high-strength structural countersunk bolts and nuts of system HR suitable for preloaded joints with thread sizes M12 to M36 and bolt property classes 8.8 and 10.9 and EN 14399-2 for suitability testing.This part gives requirements for:- dimensions;- associated washer(s) according to EN 14399-5 or to EN 14399-6;- performance and suitability tests;- for assemblies with thread sizes M12 to M36 and bolt property