Preloaded assemblies k-Class K1 and K2 manufactured in the UK
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. Other sizes, starting from M24 up to M36, and assemblies k-class K1 are subject to availability and minimum order quantity. Extended lead time may apply. M12 assemblies manufactured by Andrews Fasteners are supplied as k-class K0 only.
Where not specified by the customer, all CE Marked assemblies are supplied to k-class K0 use normally for installation with Direct Tension Indicators Washers.
Direct Tensions Indicator Washers (DTI Washers) are a specially designed component, allowing precise tension (preload) to assure correct force and reduce the risk of nut loosening or overtightening.
- Instruction Manual for installing Preloaded bolting with Direct Tension Indicators Washers EN 14399-9
DTI Washers are used with k-class K0 preload bolt assemblies as a most popular tightening method, but can also be used with k-class K1 and K2. Where, due to limited accessibility or any other reason, DTI washers cannot be used, other tightening methods can be used i.e.:
- Combined method – torque and angle – k-class K1
- Torque Method – k-class K2
- Part-Turn – k-class K0
High strength friction grip / structural bolting for preloading are supplied in two grades – Grade HR8.8 and HR10.9 – and in different coatings – such as Self-Colour, Galvanised, Zinc Plated and Sherardized.
Depending on the grade and selected tightening method, an additional component is required for installation (bolt face washer, nut face washer, direct tension indicators washer), which is not a standard part of the CE assembly.
Andrews Fasteners is an ISO 9001 and National Highway Sector Scheme 3 approved manufacturer of CE Marked fasteners to EN 14399-1 Preload bolt assemblies and EN 15048-1 Non-preloaded bolt assemblies. We are accredited and approved by Lloyds Register.
CE Marked fasteners shall be supplied as bolt, nut and washer (or washers) assemblies by one manufacturer, who will take responsibility for functions of the assembly as declared on Declaration of Performance.
- See our section for Declaration of Performances
We are also offering other types of products, which you can read about in our products section.
Our customers can always rely on our technical advice. Starting from our technical support, frequently asked question page, our continuously growing page with extracts from various standards, through email or by phone call.
For more information, please contact our Sales Team.