Content with Direct Tension Indicators

12 January 2022
We understand the difficulties by the end-users and purchasing departments in choosing the right components for different installation methods of High-strength structural bolting assemblies for preloading (HR). Different installation methods and product grades may require additional components like DTI washers, hardened washers, bolt face or nut face washers. Sometimes, the number and type of component change, depending on which part is rotated (the nut or the bolt head). We have prepared the HR configurator below to simplify this task.
Read more about BS EN 14399 (HR) Configurator

29 March 2017
Andrews Fasteners is one of only few companies available on the local market, that is capable of manufacturing in the UK k-class K1 and K2 high strength structural preloaded bolt assemblies (System HR, EN 14399-1) for tightening with predefined torque values according to the k-factor. We are able to supply CE Marked preload bolt assemblies, for hexagon head and countersunk head bolts in k-class K2 for diameters M16 and M20 with the shortest lead time.
Read more about Preloaded assemblies k-Class K1 and K2 manufactured in the UK

12 April 2016
Load curve graph for DTI for test compression loads at 0.40mm gap For use with bolts Compression load (kN) diameter Designation H8 Designation H10 M12 47-56 59-71 M16 88-106 110-132 M20 137-164 172-206 M22 170-204 212-254 M24 198-238 247-296 M27 257-308 321-385 M30 314-377 393-472 M36 458-550 572-688 According to EN 14399-9:2018, Table 4 DownloadPDF
Read more about BS EN 14399-9 Compression loads for DTI washers

08 April 2016
Direct Tension Indicators Washer – dimensions Dimensions of compressible washer-type direct tension indicator According to BS EN 14399-9:2018, Table 2 Size bolt diameter Internal diameter d1 External diameter d2 Thickness h1 Height over protrusion h2 Height of protrusions h3 Protrusion tangential diameter d3 Protrusion internal diameter d4 min max min max min max min max min M12 12,75 12,85 26,0 32,5 2,5 5,5 0,8 20,0 13,85 M16 16,75 16,85 35,0 36,8 3,0 6,0 0,8 25,0 17,85 M20 20,95 21,05 41,0 46,0 3,5 6,5 0,8 29,0 22,05 M22 23,05 23,15 46,5 50,6 4,0 7,0 0,8 33,0 24,15 M24 25,15 25,25 50,0 55,2 4,0 7,0 0,8 38,0 26,25 M27 28,30 28,40 54,0 62,1 4,0 7,0 0,8 43,0 29,40 M30 31,45 31,55 59,0 69,0 4,0 7,0 0,8 46,5 32,55 M36 37,75 37,85 78,0 83,0 4,0 7,5 0,8 56,0 38,85 Dimensions in millimetres DownloadPDF
Read more about BS EN 14399-9 Dimensions of Direct Tension Indicators washers

01 February 2015
Direct Tension Indicators Washers (BS EN 14399-9) Andrews Fasteners company in manufacturing Direct Tension Indicators Washers (DTI Washers) in well know in construction industry company based in United States – TurnaSure . All our washers are marked with our headmark FAST (previously AND.). Benefits of using Direct Tensions Indicators Washers: The use of DTIs is the simplest way of ensuring that bolting assemblies are tensioned properly; The use of DTIs saves cost on inspection ; No torque figures are required, only feeler gauges; Risk reduction on over tightening; DTIs are manufactured in compliance with EN 14399-9 and can be supplied with CE approved preload bolting assemblies; Unique curved protrusion design of Turnasure DTIs reduce necessary of using nut face / bolt face washers for 8.
Read more about Direct Tension Indicators Washers (BS EN 14399-9)