What Makes a Padlock High Security?

Qube Magazine

Facilities management professionals understand the value of good security. Although most premises nowadays are secured by advanced entrance locking mechanisms, padlocks still have a lot of uses around a property – whether it be locking an out building, a bike shed, warehouse doors or external gates.

If you are going to use padlocks to secure part of a property, you want to be able to trust they will do the job. Plenty of padlocks are available that are labelled ‘high security’ – but what exactly does that mean?

Here, online padlocks specialist Locks Direct explains the criteria that earns a padlock a high security rating, and what to look out for when you make your choice.

The CEN rating

CEN is the standardised European system for rating the security of padlocks. Under the CEN system, padlocks are rated one to six, with six being the most secure.

What is interesting for end users to know is the criteria padlocks are assessed against when undergoing CEN testing. CEN testing essentially puts a padlock through its paces against all the different ways a thief might try to break the lock, including:

  • Resistance to force and torque on the locking mechanism
  • Resistance to pulling and twisting on the shackle and staple
  • Resistance to cutting the shackle and staple
  • Resistance to impact on the padlock body
  • Resistance to drilling the padlock body.

Each grading has a minimum level the padlock must achieve for all of these criteria – if the lock fails on just one, it cannot get the higher level rating. CEN ratings 5 and 6 are usually considered high security.

Type of shackle

Assuming the body is made of tough, impact- and drill-resistant material, the shackle is usually considered the weak point of a padlock. Thieves will often try to cut or twist the shackle to break the lock.

All high CEN rated padlocks will have shackles made out of materials that are difficult to cut or break by twisting. But the design of a shackle can also play its part. Long shackle padlocks, for example, are more vulnerable to twisting, while closed shackle locks are designed not to give enough access for a cutting tool to be inserted.

However, you may need a long shackle to reach through the hasp and staple you are using. Closed shackles are very short so can only be used in limited circumstances.

Locking mechanism

Whether a key or combination lock, a padlock with a high CEN rating will have the same high number of key differs – the permutations, or different component and tolerance combinations, needed to unlock it. In a combination lock, this will equate to a very high number of possible codes, making it very difficult to crack. In a key lock, a high differs score will make it more difficult to pick.

One important thing to consider is how easy a padlock might be to shim open – the trick of inserting pieces of thin metal between the shackle and body to manipulate the locking mechanism. Double lock padlocks, or those which lock in two different places on the shackle, are much more difficult to shim open. Also look out for locks with ball bearing mechanisms, which are very difficult to manipulate in this way.

For more information on high security padlocks, visit here.

What Makes a Padlock High Security?