Nord-Lock created the original wedge-locking technology that secures bolted joints, even when exposed to severe vibration and dynamic loads. It is impossible for our products to loosen unintentionally due to the wedge created underneath the bolt head and nut.

Steel Construction Washers

Nord-Locks CE marked steel construction (SC) washers are specially designed for use on steel construction applications and to fit HV/HR sets bolts and nuts in accordance with the European standard EN 14399-3
/EN 14399-4 /EN 14399-8.

In order to ensure an optimal contact surface between the bolt and the washer, each SC-washer pair has chamfers on the inner diameter. Since the chamfer is present on both sides of each pair, it eliminates the risk of incorrect installation of the washer.

Nord-Lock steel construction washer promises the highest corrosion resistance in the market, it is tested at least 1,000 hours in the Neutral Salt Spray Test.

Washer Specifications

Material Steel 1.7182 or equivalent
Hardness HV1 > 465 HV through hardened
Surface coating Zinc flake coated free of cadmium + chrome VI
Available range M12 – M36 (NL12SC – NL36SC)



  • Secures bolted joints in structural steelwork
  • Designed and approved for use with HV sets
  • Locking function not affected by lubrication
  • Defined and uniform friction condition, which results in less deviation of achieved preload
  • Same temperature characteristics as standard bolt / nut
  • Reliable locking even for joints with short clamp length
  • High corrosion resistance (minimum 1,000 hours insalt spray test according to ISO 9227) corresponds to C4 high or C5 medium according to ISO 12944-6
  • Quick to install and remove using standard tools
  • Reusable

Testing & Certification

Nord-Locks CE marked SC-washers have been rigorously tested and approved by independent institutes as well as certification authorities. They are safe to use with high-strength structural bolting assemblies for preloading and are confirmed for HV-assemblies by the European Technical Assessment ETA-20/0010 issued by the German Institute for Construction Technology (DIBt).
SC-washers, NLO, NLSS and 254 SMO® are safe to use in non-preloaded structural bolting assemblies according EN 15048 and confirmed by the ETA-19/0813 issued by the DIBt.

More insights and references