Content with EN 14399

The clamp length is the distance between the bolt head and the nut holding all the components together. It includes steelwork, any shims, plates and washers used. The grip length is the thickness of the steelwork (that includes plates, shims etc.) that can be gripped together by the bolt and nut assembly. It strictly depends on the specific application (how many washers are used in the assembly). Example For EN 14399-3 hexagon bolt assembly type HR , diameter M30 and 100mm in length, the reference clamp length will be between 48mm up to 69mm, whereas the grip length with one washer will be 44-63mm and two washers 40-57mm.
Read more about What is the difference between Clamp length and Grip length in EN 14399 assemblies? ↬

Apart from dimensional differences ( bigger heads of bolts and bigger nuts on preloaded assemblies), the main difference is in the way how these goods are installed. Non-preloaded bolting assemblies are generally tightened to at least snug-tight. The connected components are drawn together to achieve firm contact without any specific preload. The “snug-tight” is generally referenced as tightening the assembly by one man using a normal-sized spanner without an extension arm until the wrench starts hammering.
Read more about What is the difference between preloaded and non-preloaded bolting assemblies? ↬

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).
Read more about BS EN 14399 High-Strength Structural Bolting Assemblies for Preload Configurator (HR) ↬

When ordering Preloaded Assemblies (EN 14399-1) to be installed with Direct Tension Indicator Washers (DTIs) , there are 4 different methods of how they can be installed. Depending on the access or preference, you may choose one method, over another. At the purchase stage, we may not know how you will be installing your assemblies. Please read below, as you may require an additional washer(s) to be purchased. Figure 1 Figure 2 Figure 3 Figure 4 Installation methods: Installing DTI under the bolt head when the nut is rotated (Figure 1)
Read more about Do I need Bolt Face Washer or Nut Face Washer (EN 14399-9) with DTI's? ↬

Following certification renewal audit carried out by Lloyd’s Register Quality Assurance (LRQA) on 31st January 2018 and 1st February 2018, Andrews Fasteners Limited has been found to comply with the requirements and been recommended for the renewal of its certificates for ISO 9001:2015, National Highway Sector Scheme 3 (NHSS 3) and Construction Product Regulations approvals (EN 15048-1:2007 and EN 14399-1:2015). Our final certificates, once issued will be published on our Certificates and Approvals section.
Read more about Andrews Fasteners Limited - Certificate Renewal (2018) ↬

High-strength structural bolting assemblies for preloading with specified k-Class shall be tightened using below methods (See BS EN 1090-2:2008+A1:2011, Table 20 for more details). Method k-Class Torque method K2 Combined method (torque / part-turn) K2 or K1 Direct Tension Indicators (DTI) K2, K1 or K0 k-Class K2 using Torque Method Torque method uses a torque wrench in two steps of assembling. km figure is required for calculating first tightening torque value and Vk is required for calculating final tightening torque.
Read more about Torque values for High-Strength Structural Bolting Assemblies for Preloading with specified k-Class ↬

Andrews Fasteners Limited, following recent transitional process with Lloyd’s Register Quality Assurance (LRQA) gained approval to the latest version of EN 14399-1:2015. We are proud to be the first company in the United Kingdom to become approved to the latest edition of the standard and one of the first companies in the world. Following new approvals, new assemblies for preloading will be associated with a new type of CE Labels and a new layout of Declaration of Performances following the strict requirements of the new standard.
Read more about Andrews Fasteners Limited – The first fastener company to be approved to EN 14399-1:2015 ↬

Due to the compression ability of paint, galvanising coating and other types of surface protection , it is required that places of joints for high-strength structural bolting assemblies for preloading are cleaned from any coating before installation. After the installation process, depending on the type of coating of the assemblies, the whole surface can be further covered to restore corrosion protection in joint places. Please refer to EN 1090-2:2018 pt. 8.
Read more about Can high-strength structural bolting assemblies for preloading (HSFG) be used on painted or galvanised surfaces? ↬