Selection Guide

Nord-Lock washer material / type

Nord-Lock washers are available in the following materials:

Application parameter
Steel Stainless
steel (ss)
Steel type
EN 1.7182 or equivalent EN 1.4404 or equivalent EN 1.4547 or equivalent EN 2.4819 or equivalent EN 2.4668 or equivalent
Examples of applications
General steel
General stainless steel applications.
Non chlorine / acid environments
General salt water
applications, pumps,
chloride applications,
heat exchangers, nuclear,
desalination, food
processing & medical
General acidic
environments, process
and chemical industry,
evaporators, offshore
downhole tooling
Applications with high temperatures, gas turbines, turbo charges, incinerators
Available for bolt sizes

#5 to 5″


#5 to 3 1/8″


#5 to 1 1/2″

M3-M39 available on request

#5 to 1 1/2″ available on request

M3-M39 available on request

#5 to 1 1/2″ available on request

Washer types
Regular outer diameter (NL3 – NL130)

Enlarged outer diameter (NL3,5sp – NL36sp)

Regular outer diameter (NL3ss-NL80ss)

Enlarged outer diameter (NL3,5spss – NL30spss)

Regular outer diameter (NL3ss-254 – NL39ss-254)

Enlarged outer diameter (NL3,5spss-254 – NL27spss-254)

Regular outer diameter (NL3ss-276 – NL39ss-276)

Enlarged outer diameter (NL3,5spss-276 – NL27spss-276)

Regular outer diameter (NL3ss-718 – NL39ss-718)

Enlarged outer diameter (NL3,5spss-718 – NL27spss-718)

Treatment surface coating
Through hardened
Delta Protekt® base coat
(KL100) and top coat
Surface hardened Surface hardened Surface hardened Surface hardened
Washer hardness*
≥ 465HV1 ≥ 520HV0,05 ≥ 600HV0,05 ≥ 520HV0,05 ≥ 620HV0,05
Corrosion resistance
Minimum 600 hours in salt spray test
(according to IS09227)
PREN 27** PREN 45** PREN 68** PREN 29**
Bolt grades
Up to 12.9 Up to A4-80 Up to A4-80 Up to A4-80 Up to A4-80
Temperature range***
-50°C to 200°C -160°C to 500°C -160°C to 500°C -160°C to 500°C -160°C to 700°C


* In order to assure the unique mechanical locking function of the Nord-Lock washers, the hardness of the mating surfaces must be lower than the hardness of the Nord-Lock washers (see table above). Go to washer hardness page for a hardness conversion table.

** PREN (Pitting Resistance Equivalent Number) = %Cr + 3,3x%Mo + 16x%N. Figures in table valid for base material.

*** Temperature recommendations based on information from the raw material supplier and from tests. Locking function not affected within the specification.