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Flat Washers and Non-preloaded Bolt and Nut Assemblies.

BS EN ISO 898-3 was published in July 2018: Mechanical properties of fasteners made of carbon and alloy steel – Part 3: Flat washers with specified property classes.

Table 1 in the standard does not permit 100 HV (Vickers Hardness) washers to be used with 8.8/8 and 10.9/10 bolt and nut assemblies.

However, the UK National foreword to BS EN ISO 898-3 recommends that for structural bolting assemblies required for EN 1090-2 non-preloaded connections this aspect of ISO 898-3: 2018 should be disregarded.

In addition, the National Structural Steelwork Specification and the Model Specification for the Purchase of Structural Bolting Assemblies and Holding Down Bolts permit the use of HV 100 washers for these assemblies. Moreover, EN 15048-1:2007 clause or EN 15048-2: 2016 clause 5.2 defines the requirement for washers in non-preloaded bolting assemblies.

Thomas Cosgrove 

Fabrication & Welding Manager,