What is BS EN 14399-5 - Plain washers about?
BS EN 14399 is a series of European standards on structural bolting assemblies that discusses the dimension and general requirements of plain washers. BS EN 14399-5 is the fifth part of a series of documents on structural bolting assemblies.
BS EN 14399-5 specifies, together with EN 14399-1 and EN 14399-2, hardened and tempered plain washers intended for bolting assemblies with large series hexagon high-strength structural bolts and nuts with threads from M12 to M36 inclusive. Washers according to BS EN 14399-5 can be applied under the nut only.
Washers according to this standard are not intended to be used in direct contact with oversized or slotted holes.
NOTE: Attention is drawn to the importance of ensuring that the washers are correctly used if satisfactory results are to be obtained. For recommendations concerning the proper application, reference to EN 1090-2 is made.
Who is BS EN 14399-5 - Plain washers for?
BS EN 14399-5 on high-strength structural bolting assemblies for preloading is relevant to:
- Manufacturer of plain washer
Why should you use BS EN 14399-5 - Plain washers?
Plain washers, also known as flat washers, are the most common type of washer. Plain washers do not have a locking function, rather they are used to protect the mating surface from damage.
BS EN 14399-5 provides guidance on dimensions, specifications and reference standards, designation.
BS EN 14399-5 exemplifies the required dimensions that help you achieve precision in terms of product functionality and specification. With obedience and compliance to BS EN 14399-5, you can efficiently manufacture plain washers of precise dimension. With BS EN 14399-5 you can be ensured that the products consistently meet and exceed quality assurance targets.
What’s changed since the last update?
BS EN 14399-5:2015 supersedes BS EN 14399-5:2005 which is withdrawn.
In comparison with EN 14399-5:2005, the following modifications have been made:
- Table 1 containing the overview of the composition of bolting assemblies and component marking has been added
- A washer with a larger value of d2 (marked HD for HRD nuts) that may be supplied by agreement between customer and manufacturer has been added
- Specifications for the marking of washers have been revised

