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 chamfered plain washers.
  • Mating surfaces that are not locked in place.
  • Mating surfaces harder than the washers.
  • Extremely soft mating surfaces (e.g. wood, plastic).
  • Applications with extremely large settlements.

Torque Guidelines

Please note that the torque guidelines below are valid for HV bolts only.

Washer size


Reduce preload force
F (P, C, NL*)

Modified torque method
Torque moment
M (A, L)

Modified combined method* (torque + angle)
Pre-torque moment

NL12SC 45 130 100
NL16SC 90 330 250
NL20SC 145 660 490
NL22SC 170 850 640
NL24SC 200 1100 825
NL27SC 260 1600 1220
NL30SC 315 2150 1650
NL36SC 460 3750 2800
*Torque conditions are specified in the ETA-13/0246 for HV bolts, grade 10.9

Tightening Angles

t < 2d 45° 1/8
2d ≤ t < 6d 60° 1/8
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.

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