{"id":70088,"date":"2026-05-17T17:29:47","date_gmt":"2026-05-17T17:29:47","guid":{"rendered":"https:\/\/evgroupchina.com\/encyclopedia-of-metal\/en-14399\/"},"modified":"2026-05-19T15:33:27","modified_gmt":"2026-05-19T15:33:27","slug":"en-14399","status":"publish","type":"wiki","link":"https:\/\/evgroupchina.com\/en\/encyclopedia-of-metal\/en-14399\/","title":{"rendered":"EN 14399"},"content":{"rendered":"<h2>Overview of the EN 14399 Standard Series<\/h2>\n<p>The EN 14399 standard series regulates the production and application of high-strength structural bolting assemblies intended for preloading in steel structures. EV Group China presents an expert breakdown of the technical requirements for HR, HV, and HRC system components.<\/p>\n<h2>EN 14399-1: General Requirements<\/h2>\n<p>The standard establishes basic requirements for assemblies (bolt-nut-washer). EV Group China\u2019s products comply with these standards to ensure the reliability of steel structures.<\/p>\n<ul>\n<li>Products smaller than M12 are not intended for preloading.<\/li>\n<li>Bolting assemblies must not be welded.<\/li>\n<li>The standard does not apply to components for railway tracks.<\/li>\n<\/ul>\n<h2>EN 14399-2: Suitability for Preloading<\/h2>\n<p>Defines test methods that guarantee the assembly will maintain the design preload force when installed according to EN 1090-2, ensuring the necessary degree of ductility.<\/p>\n<h2>EN 14399-3: HR System (High Resistance)<\/h2>\n<p>Technical requirements for bolts and nuts with large widths across flats. Diameter range: M12\u2013M36. Property classes: 8.8\/8, 8.8\/10, 10.9\/10.<\/p>\n<table class=\"table table-bordered table-hover\">\n<thead>\n<tr>\n<th>Parameter<\/th>\n<th>Description<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Nut type<\/td>\n<td>Standard height (type 1) according to EN ISO 4032<\/td>\n<\/tr>\n<tr>\n<td>Thread length<\/td>\n<td>In accordance with ISO 888<\/td>\n<\/tr>\n<tr>\n<td>Application<\/td>\n<td>Steel structures under high loads<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>EN 14399-4: HV System (High Voltage)<\/h2>\n<p>Regulates HV assemblies with thread sizes M12\u2013M36 and class 10.9\/10. Ductility is achieved through deformation of the threaded part. Nuts have a height of 0.8d.<\/p>\n<h2>EN 14399-5 and EN 14399-6: Washers<\/h2>\n<p>These standards describe requirements for hardened flat washers (part 5) and chamfered washers (part 6) for assembling high-strength bolting units.<\/p>\n<h2>EN 14399-7 and EN 14399-8: Countersunk and Hexagon Modifications<\/h2>\n<p>Specialized standards for countersunk head bolts (HR) and standard hexagon bolts (HV) with increased shaft diameters.<\/p>\n<h2>EN 14399-9: Direct Tension Indicators<\/h2>\n<p>Regulates the use of Direct Tension Indicators (DTI), which allow for visual inspection of the achieved design preload in HR and HV systems.<\/p>\n<h2>EN 14399-10: HRC System (High Resistance Calibrated)<\/h2>\n<p>Describes bolting assemblies with calibrated preload. The system includes bolts with hexagon or domed heads, ensuring controlled plastic elongation of the shank.<\/p>\n","protected":false},"featured_media":0,"template":"","meta":[],"wiki_category":[114],"class_list":["post-70088","wiki","type-wiki","status-publish","hentry","wiki_category-en"],"_links":{"self":[{"href":"https:\/\/evgroupchina.com\/en\/wp-json\/wp\/v2\/wiki\/70088","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/evgroupchina.com\/en\/wp-json\/wp\/v2\/wiki"}],"about":[{"href":"https:\/\/evgroupchina.com\/en\/wp-json\/wp\/v2\/types\/wiki"}],"version-history":[{"count":0,"href":"https:\/\/evgroupchina.com\/en\/wp-json\/wp\/v2\/wiki\/70088\/revisions"}],"wp:attachment":[{"href":"https:\/\/evgroupchina.com\/en\/wp-json\/wp\/v2\/media?parent=70088"}],"wp:term":[{"taxonomy":"wiki_category","embeddable":true,"href":"https:\/\/evgroupchina.com\/en\/wp-json\/wp\/v2\/wiki_category?post=70088"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}