Steel Construction Washers

Steel Construction Washers

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.

Joint Guide

Nord-Lock SC-washers can be used with HV / HR bolts and nuts.

Through-holes require the use of two pairs of Nord-Lock SC-washers. One pair for securing the bolt and a second pair for securing the nut. Turn both fasteners in order to close the cams on both washer pairs before tightening to minimize settlements. Keep the bolt secure whilst tightening the nut.

Designs where Nord-Lock SC-washers are not recommended:

  • With plain washers
  • When mating surfaces are not locked in place
  • When mating surfaces are harder than the washers
  • With very soft mating surfaces — for example, wood and plastic
  • For applications with extremely large settlements
  • When there is no clamping force in the joint

Torque Guidelines

Note that the torque guidelines below only apply to HV bolts with NLSC washers.



Reduced preload force
F *

torque method


Modified combined
method [torque + angle]
M *

Minimum torque


NL12SC 45 130   100 80
NL16SC 90 330   250 200
NL20SC 145 660   490 360
NL22SC 170 850   640 520
NL24SC 200 1100   825 640
NL27SC 260 1600   1220 1000
NL30SC 315 2150   1650 1320
NL36SC 460 3750   2800 2240

*Tightening conditions are specified in ETA-13/0246 for HV bolts, grade 10.9.

Required angle of further rotation

Clamp length angle part tum
t < 2d 45° 1/8
2d ≤ t < 6d 60° 1/6
6d ≤ t ≤ 10d 90° 1/4
10d < t No recommendations
Tightening angles when using the combined method varies depending on the clamp length, (t), in relation to bolt diameter, (d).

More insights and references