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.

NORD-LOCK STEEL WASHERS

Applications General steel applications
Material standard EN 1.7182
Size range M3-M130
#5 to 5"
Corrosion resistance Minimum 1,000 hours in salt spray test (according to ISO 9227)
Hardening Through hardened
Washer hardness* ≥ 465HV1
Coating Basecoat Delta Protekt® KL100, Topcoat VH 302 GZ   
Bolt grades Up to 12.9
Temperature range*** -50°C to 200°C
Product designation NL
NLsp
Laser marking type code Traceable batch number and type code flZn

* Washer hardness must be greater than the hardness of the mating surfaces in order to assure its mechanical function.

*** Temperature recommendations are based on information from the raw material supplier and testing. The locking function is not affected within the specified range.

NORD-LOCK STAINLESS STEEL WASHERS

Applications General stainless steel applications
Material standard EN 1.4404
Size range M3-M80 
#5 to 3 1/8"
Corrosion resistance PREN 27**
Hardening Surface hardened
Washer hardness* ≥ 520HV0,05
Bolt grades Up to A4-80
Temperature range*** -160°C to 500°C
Product designation NLss
NLspss
Laser marking type code SS

 

* 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. 

** 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.

NORD-LOCK 254 SMO® WASHERS

Applications Corrosive environment – chloride rich environments, offshore, pumps, heat exchangers, nuclear, food, medical, processing
Material standard EN 1.4547
Size range M3-M39
#5 to 1 1/2"
Corrosion resistance PREN 45**
Hardening Surface hardened
Washer hardness* ≥ 600HV0,05
Temperature range*** -160°C to 500°C
Product designation NLss-254
NLspss-254
Laser marking type code 254

 

* 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. 

** 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.

 

Nord-Lock Alloy C-276 Washers

Applications Acidic environment – chemical industry, evaporators, offshore, downhole tooling
Material standard EN 2.4819 or equivalent
Size range M4-M20
#8 to 1 1/2"
Corrosion resistance PREN 68**
Hardening Surface hardened
Washer hardness* ≥ 520HV0,05
Temperature range*** -160°C to 500°C
Product designation NLss-276
NLspss-276
Laser marking type code 276

 

* 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. 

** 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.

Nord-Lock Alloy 718 Washers

Applications High temperatures – gas turbines, turbo charges, incinerators
Material standard EN 2.4668 or equivalent
Size range M4-M20
#5 to 1 1/2"
Corrosion resistance PREN 29**
Hardening Surface hardened
Washer hardness* ≥ 620HV0,05
Temperature range*** -160°C to 700°C
Product designation NLss-718
NLspss-718
Laser marking type code 718

 

* 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. 

** 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.

All types of Nord-Lock washers

Material type
Steel Stainless
steel (ss)
254 SMO® ALLOY 
C-276
ALLOY
718
Applications
General steel applications General stainless steel applications Corrosive environment – chloride rich environments, offshore, pumps, heat exchangers, nuclear, food, medical, processing Acidic environment – chemical industry, evaporators, offshore, downhole tooling High temperatures – gas turbines, turbo charges, incinerators
Material standard
EN 1.7182 EN 1.4404 EN 1.4547 EN 2.4819 or equivalent EN 2.4668 or equivalent
Size range

M3-M130

#5 to 5"

M3-M80

#5 to 3 1/8"

M3-M39

#5 to 1 1/2"

M4-M20

#8 to 1 1/2"

M4-M20

#5 to 1 1/2"

Corrosion resistance
Minimum 1,000 hours in salt spray test (according to ISO 9227) PREN 27** PREN 45** PREN 68** PREN 29**
Hardening
Through hardened Surface hardened Surface hardened Surface hardened Surface hardened
Washer hardness*
≥ 465HV1 ≥ 520HV0,05 ≥ 600HV0,05 ≥ 520HV0,05 ≥ 620HV0,05
Coating
Delta Protekt® KL100 zinc flake coating - - - -
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
Product designation
NL
NLsp
NLss
NLspss
NLss-254
NLspss-254
NLss-276
NLspss-276
NLss-718
NLspss-718
Laser marking type code
flZn SS 254 276 718

 

* 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. 

** 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.

Selection Guide

Application parameter
Steel Stainless
steel (ss)
254 SMO® ALLOY 
C-276
ALLOY
718
Steel type
EN 1.7182 EN 1.4404 EN 1.4547 EN 2.4819 or equivalent EN 2.4668 or equivalent
Examples of applications
General steel applications General stainless steel applications. Non chlorine / acid environments General salt water applications, pumps, chloride applications, heat exchangers, nuclear, desalination, food processing & medical equipment General acidic environments, process and chemical industry, evaporators, offshore downhole tooling Applications with high temperatures, gas turbines, turbo charges, incinerators
Available for bolt sizes

M3-M130

#5 to 5"

M3-M80

#5 to 3 1/8"

M3-M39

#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 (VH302GZ) Surface hardened Surface hardened Surface hardened Surface hardened
Washer hardness*
≥ 465HV1 ≥ 520HV0,05 ≥ 600HV0,05 ≥ 520HV0,05 ≥ 620HV0,05
Corrosion resistance
Minimum 1,000 hours in salt spray test (according to IS09227) PREN 26** PREN 45** PREN 68** PREN 29**
Bolt grades
Up to 12.9 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. 

** 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.

Hardness Conversion Table

Vickers
HV
Brinell
HB
Rockwell HRC Rockwell HRA 8.8
bolt
10.9 bolt 12.9 bolt
300 285 29,8 65,5 |    
310 295 31,0 65,8 |    
320 304 32,2 66,4 | 320 HV  
330 314 33,3 67,0 | |  
335 319 33,9 67,3 335 HV |  
340 325 34,4 67,6   |  
350 333 35,5 68,1   |  
360 342 36,6 68,7   |  
370 352 37,7 69,2   |  
380 361 38,8 69,8   380 HV  
385 366 39,3 70,1     385 HV
390 371 39,8 70,3     |
400 380 40,8 70,8     |
410 390 41,8 71,4     |
420 399 42,7 71,8     |
430 409 43,6 72,3     |
435 414 44,1 72,5     435 HV
440 418 44,5 72,8      
460 437 46,1 73,6      
480 (456) 47,7 74,5      
500 (475) 49,1 75,3      
520 (494) 50,5 76,1      
540 (513) 51,7 76,7      

Customer success stories

Buy Nord-Lock washers online

Nord-Lock washers in blister packages are now available. Use the following selector to find the washers you need!

1. Bolt size

2. Washer material

3. Washer outer diameter