BS EN 14399 High-strength structural bolting assemblies for preloading (CE & UKCA Marked)

BS EN 14399-3 Hexagon bolting assemblies for preloading (HR)

Previously known as High Strength Friction Grip (HSFG)

We are a manufacturer of UKCA & CE Marked pre-loaded fasteners to BS EN 14399. In our facility in Leeds, we can UKCA & CE Approve – assembly test to BS EN 14399-2 HR Assemblies from M12 to M36 up to grade 10.9. We are regularly independently assessed by Lloyd’s Register / LRQA, to make sure, that our company is fully compliant with BS EN 14399 requirements.

Typical assemblies to BS EN 14399 include hexagon head bolt (HR Bolt) to BS EN 14399-3 , hexagon nut to EN 14399-3 and hard washer to BS EN 14399-5 (used under the nut) or chamfered hard washer BS EN 14399-6 (usually used under bolt head). Additionally, for full compliance with k-Class k0, our company supply Direct Tensions Indicator washers to BS EN 14399-9 . For grade 10.9 assemblies, together with DTI washers supplied are hard washers (bolt face or nut face washers) to BS EN 14399-9 which are used on top of the DTI washer.

BS EN 14399-7 Countersunk Bolts (HR CSK)

We are approved to supply UKCA & CE Marked Countersunk head bolting assemblies. These assemblies include Countersunk slotted round head bolt (90-degree angle) to BS EN 14399-7 together with Hexagon head nut to BS EN 14399-7/3 and washers to BS EN 14399-5/6. HR CSK assemblies are tested according to BS EN 14399-2 requirements and UKCA & CE Marked. Assemblies to k-Class k0 supplied are with DTI washers to BS EN 14399-9 and nut face washers to BS EN 14399-9 (for grade 10.9).

We are offering UKCA & CE pre-loaded assemblies HR from M12 up to M36 and HR CSK from M16 up to M30 with shortest lead time on the market and possibility to manufacture assemblies based on customer requirements to specified length and grade.

BS EN 14399-9 Direct Tension Indicators (DTI)

Direct tensions indicator washers (DTI) to BS EN 14399-9 are supplied with k-Class k0 HR and HR CSK assemblies. DTI washers are used during tightening of the assemblies, to ensure, that correct force for pre-loaded fasteners is achieved. DTI washers reduce necessary to use Torque figures and risk of over-tightening of the assemblies.

DescriptionSpecificationSize range
Hexagon Bolts (HR)BS EN 14399-3
Alternative to BS 4395-1, BS 4395-2, ASTM A325M & ASTM A490M, DIN 6914
Hexagon Nut – fullnut (HR)BS EN 14399-3 & 14399-7
Alternative to BS 4395-1, BS 4395-2, ASTM A563M, DIN 6915
HR Assembly
Hexagon Bolt, Nut, Washer
BS EN 14399-1
Bolt assembly for preloading for use in accordance with a defined k-class
Countersunk Bolts (HR)BS EN 14399-7M12–M36
HR CSK Assembly
Countersunk bolt, Nut, Washer
BS EN 14399-1
Bolt assembly for preloading for use in accordance with a defined k-class
M16 – M30
Hardened Washers min. 300 HVBS EN 14399-5 & 14399-6
Alternative to BS 4395-1, BS 4395-2, ASTM A436M, DIN 6916 & 6917 & 6918
Bolt Face / Nut Face WashersBS EN 14399-9
Alternative to BS 7644-2
Direct Tension Indicators Washers (DTI Washers)BS EN 14399-9
Alternative to BS 7644-1, ASTM F959M

Size range available


() - These sizes are rarely available and are made on special request (min. 1 pallet quantity may be required).

Thread Classes

BS EN 14399-3 Hexagon Head Bolt6gBS EN 14399-3 Nut6H6AZ6AZ
BS EN 14399-7 Countersunk Bolt6gBS EN 14399-7 Nut6H6AZ6AZ

*) Recommendation of the sherardizer

Finishes available

Self Colour
Bare / Blackened (Black Oxide)
Lightly Oiled
Hot Dip Galvanised
EN ISO 10684
EN ISO 1461
BS 7371-6
Sherardized Vapour galvanising
EN ISO 17668
EN 13811
BS 7371-8
BS 4921
Bright Zinc Plated
EN ISO 4042
BS 7371-3
Mechanical Applied Coating (Galvanized/Zinc)
BS 7371-7

Looking for ASTM Alternative (A325M, A490M, A563M, F436M)?

Look in our comparison article to EN 14399 Pre-load bolt assemblies.