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What does the CEN grade mean on a padlock?

Updated on Jan 25, 2025

You might have seen a CEN Rating on a padlock and wondered what it is.

The CEN grade stands for Central European Norm and it's a padlock testing standard.

The CEN standard was developed by major padlock manufacturers as a way of proving the quality of their products.

The European Union formally recognises several European Standardisation Organisations, including CEN, as being in charge of creating and establishing these voluntary standards. CEN is similar to Sold Secure, which is a more commonly known testing standard in the UK.

CEN Grades #

The CEN grade is divided into six tiers, from maximum security to wider use. A CEN Grade 1 padlock is typically something like a school locker combination padlock.

Padlocks with CEN Grade 6 certification offer the maximum attack resistance and are the locks usually stipulated for maximum security commerical applications. We sell the Squire SS80CS which is a CEN Grade 6 padlock. CEN grades 3-5 are typically recommended by insurance companies for consumer applications.

GRADE 6 – Maximum Security
GRADE 5 – Extra High Security
GRADE 4 – High Security
GRADE 3 – Medium / High Security
GRADE 2 – Standard Security
GRADE 1 – Low Security

CEN Testing Criteria #

Locks are subjected to the following tests:

  • The minimum of key differences
  • Shackle/Staple Pulling (kN)
  • Twisting of the staple or shackle
  • Sustained minutes of drilling
  • Sustained minutes of angle-grinder attack
  • Shackle/Staple Cutting
  • Blow on the staple or shackle (at different temperatures)
  • Lock Body Blow (at different temperatures)
  • Locking mechanism or cylinder plug load
  • The torque resistance of the cylinder plug

The lock is graded according to the test it fails rather than just the tests it passes. So if it scores a maximum on all tests but one, it will still only be graded to the standard of the test it failed. Some may argue this is a harsh way to score a lock but it means that the standards of all CEN graded locks remain high.

CEN 5 vs CEN 6 #

Both CEN 5 rated and CEN 6 rated padlocks offer excellent levels of security. But for some customers, only the absolute best will do.

The table below shows a comparison of a CEN 5 vs CEN 6 padlock and the tests requirements it has to pass to meet those grades.

 

Requirement: CEN5 CEN6
Pulling Of Shackle/Staple:  70kN  100kN
Twisting Of Shackle/Staple:  1200Nm  2500Nm
Cutting Of Shackle/Staple:  70kN  100kN
Blow on Shackle/Staple (5 times):  6550g from a height of 1400mm at -40 degrees celsius  7150g from a height of 1500mm at -40 degrees celsius.
Blow On Lock Body (5 times):  6550g from a height of 1400mm at -40 degrees celsius  7150g from a height of 1500mm at -40 degrees celsius.
Load On Cylinder Plug Or Locking Mechanism:  10kN  15kN
Drilling (minutes):  4  8
Sawing (minutes): 4  8
Torque Resistance of Cylinder Plug:  20Nm  30Nm

In Summary #

Like all padlock testing standards, CEN is not perfect but broadly speaking it is an excellent way of quickly understanding a padlock's ability to resist attack.