EN 14399-9:2018
(Main)High-strength structural bolting assemblies for preloading - Part 9: System HR or HV - Direct tension indicators for bolt and nut assemblies
General Information
- Abstract
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).
NOTE 1 Attention is drawn to the importance of ensuring that the bolting assemblies are correctly used if satisfactory results are to be obtained. For recommendations concerning proper application, reference to EN 1090-2 is made.
General requirements and requirements for suitability for preloading are specified in EN 14399-2 together with Clause 5 of this document.
NOTE 2 Direct tension indicators are also known as load indicating washers.
- Status
- Published
- Publication Date
- 02-May-2018
- Withdrawal Date
- 04-Nov-2018
- Technical Committee
- CEN/TC 185 - Threaded and nonthreaded mechanical fasteners and accessories
- Drafting Committee
- CEN/TC 185/WG 6 - Structural bolting
- Current Stage
- 9093 - Decision to confirm - Review Enquiry
- Start Date
- 04-Dec-2023
- Completion Date
- 17-Sep-2026
Overview
EN 14399-9:2018 is the CEN European Standard that defines direct tension indicators (DTIs) - also called load indicating washers - as components of high‑strength structural bolting assemblies for preloading. Used with systems HR or HV, the standard specifies DTIs, nut face washers (HN) and bolt face washers (HB) for nominal thread sizes M12–M36 and property classes 8.8/8, 8.8/10 and 10.9/10. DTIs are designed to demonstrate that a specified preload has been reached by compressing protrusions beneath the bolt head or nut.
Key topics and technical requirements
- Scope & compatibility: EN 14399-9:2018 is applied together with EN 14399-1 (general requirements) and EN 14399-2 (suitability for preloading). DTIs are used only as part of complete bolting assemblies complying with the EN 14399 series (systems HR or HV).
- Designations & sizes: Two DTI property designations are defined - H8 and H10 - with specified general dimensions, tolerances and minimum of four protrusions distributed at equal angular intervals.
- Functional performance: Assemblies are designed to permit preloading of at least 0.7 · fub · As in accordance with EN 1993‑1‑8 (Eurocode 3). Ductility is achieved either by plastic elongation of the bolt (system HR) or by plastic deformation of engaged threads (system HV).
- Materials, coatings and marking: The standard sets requirements for materials, surface finishes and marking of DTIs, HN and HB washers. Coating control and consistent lubrication across the assembly are emphasised.
- Testing & verification: Detailed test methods are included for DTI functional testing and for measuring compression loads (test apparatus, support/bearing blocks, calibration and procedures). Suitability tests for complete bolting assemblies are required and manufacturers must supply assemblies as a matched set.
Applications and users
- Who uses it: Structural engineers, steel fabricators, fastener manufacturers, quality inspectors, procurement specialists and compliance officers specifying preloaded bolted joints in steel construction.
- Practical applications: Ensures reliable preloaded joints in structural steelwork (connections sensitive to preload), simplifies site verification of preload by visual/feeler gauge inspection of DTIs, supports compliance with Eurocode requirements and improves joint consistency where calibrated preloads or hydraulic tensioning are not used.
Related standards
- EN 14399-1, EN 14399-2, EN 14399-3, EN 14399-4, EN 14399-5, EN 14399-6, EN 14399-7, EN 14399-8, EN 14399-10 (EN 14399 series)
- EN 1993-1-8 (Eurocode 3 - design of joints)
- EN 1090-2 (execution of steel structures guidance)
- Normative test/measurement references (e.g., EN ISO standards cited within EN 14399-9)
Keywords: EN 14399-9:2018, direct tension indicators, load indicating washers, high-strength structural bolting, preloading, system HR, system HV, nut face washer, bolt face washer, preloaded joints.
Relations
- Effective Date
- 09-May-2018
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Refers
EN 14399-5:2015 - High-strength structural bolting assemblies for preloading - Part 5: Plain washers - Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
Frequently Asked Questions
EN 14399-9:2018 is a standard published by the European Committee for Standardization (CEN). Its full title is "High-strength structural bolting assemblies for preloading - Part 9: System HR or HV - Direct tension indicators for bolt and nut assemblies". This standard covers: 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). NOTE 1 Attention is drawn to the importance of ensuring that the bolting assemblies are correctly used if satisfactory results are to be obtained. For recommendations concerning proper application, reference to EN 1090-2 is made. General requirements and requirements for suitability for preloading are specified in EN 14399-2 together with Clause 5 of this document. NOTE 2 Direct tension indicators are also known as load indicating washers.
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). NOTE 1 Attention is drawn to the importance of ensuring that the bolting assemblies are correctly used if satisfactory results are to be obtained. For recommendations concerning proper application, reference to EN 1090-2 is made. General requirements and requirements for suitability for preloading are specified in EN 14399-2 together with Clause 5 of this document. NOTE 2 Direct tension indicators are also known as load indicating washers.
EN 14399-9:2018 is classified under the following ICS (International Classification for Standards) categories: 21.060.01 - Fasteners in general. The ICS classification helps identify the subject area and facilitates finding related standards.
EN 14399-9:2018 has the following relationships with other standards: It is inter standard links to EN 14399-9:2009, EN ISO 17668:2016, EN ISO 7500-1:2018, EN 14399-5:2015, EN ISO 6507-1:2023, EN 14399-1:2015, EN 14399-3:2015, EN ISO 4759-3:2016, EN ISO 3269:2000, EN 14399-4:2015, EN ISO 6508-1:2023, EN 14399-6:2015, EN 13814-1:2019+A1:2024, EN 14399-7:2018, EN 1090-2:2018. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
EN 14399-9:2018 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Hochfeste vorspannbare Garnituren für Schraubverbindungen im Metallbau - Teil 9: System HR oder HV - Direkte Kraftanzeiger für Garnituren aus Schrauben und MutternBoulonnerie de construction métallique à haute résistance apte à la précontrainte - Partie 9 : Système HR ou HV - Boulons avec rondelles indicatrices de précontrainteHigh-strength structural bolting assemblies for preloading - Part 9: System HR or HV - Direct tension indicators for bolt and nut assemblies21.060.20MaticeNuts21.060.10Sorniki, vijaki, stebelni vijakiBolts, screws, studsICS:Ta slovenski standard je istoveten z:EN 14399-9:2018SIST EN 14399-9:2018en,fr,de01-julij-2018SIST EN 14399-9:2018SLOVENSKI
STANDARDSIST EN 14399-9:20091DGRPHãþD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 14399-9
May
t r s z ICS
t sä r x rä r s Supersedes EN
s v u { {æ {ã t r r {English Version
Highæstrength structural bolting assemblies for preloading æ Part
{ã System HR or HV æ Direct tension indicators for bolt and nut assemblies Boulonnerie de construction métallique à haute résistance apte à la précontrainte æ Partie
{ ã Système HR ou HV æ Boulons avec rondelles indicatrices de précontrainte
Hochfeste vorspannbare Garnituren für Schraubverbindungen im Metallbau æ Teil
{ã System HR oder HV æ Direkte Kraftanzeiger für Garnituren aus Schrauben und Muttern This European Standard was approved by CEN on
t t October
t r s yä
egulations which stipulate the conditions for giving this European Standard the status of a national standard without any alterationä Upætoædate lists and bibliographical references concerning such national standards may be obtained on application to the CENæCENELEC Management Centre or to any CEN memberä
translation under the responsibility of a CEN member into its own language and notified to the CENæCENELEC Management Centre has the same status as the official versionsä
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t r s z CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Membersä Refä Noä EN
s v u { {æ {ã t r s z ESIST EN 14399-9:2018
Use of structural bolting assemblies for preloading with direct tension indicators . 25 A.1 General . 25 A.2 Bolting assembly configurations . 25 A.3 Checking . 26 Bibliography . 29
1) fub is the nominal tensile strength (Rm) and As is the nominal stress area of the bolt. SIST EN 14399-9:2018
Key d1 internal diameter d2 external diameter d3 protrusion tangential external diameter d4 protrusion tangential internal diameter h1 material thickness (excluding protrusions) h2 height over protrusions (including protrusions) h3 height of protrusions Figure 1 — Dimensions of direct tension indicator (example with six protrusions) Figure 1 shows a schematic representation of the protrusions (other forms including curved may be used). For coated direct tension indicators, the dimensions apply prior to coating. Direct tension indicators may have indentations or other features on the outside diameter that correspond to and are aligned with feeler gauge entry spaces to indicate where feeler gauges shall be inserted. SIST EN 14399-9:2018
3.3 Specifications and reference standards for direct tension indicators The specifications and reference standards are given in Table 3. SIST EN 14399-9:2018
3.4 Functional test of direct tension indicators The direct tension indicators shall be tested on a calibrated load-measuring device; see 3.5 for the test procedure. The load requirement of Table 4 shall be met when the direct tension indicators are compressed to the gap of 0,40 mm. Samples of direct tension indicators shall be tested by the manufacturer after the f
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