The Space Station guide to padlocks


Our business is all about security, so it stands to reason that we know a good padlock when we see one. While your belongings are protected in a number of ways here at Space Station – including CCTV, perimeter fences and night security staff – the last line of defence is the padlock on your storage unit, a pretty simple but effective piece of technology.

Padlocks have been around a long time – they were used by merchants of the Roman Empire to protect goods when travelling the trade routes to China, and padlocks with spring-loaded mechanisms were found at the Jorvik Viking settlement in York. The fact they’ve survived for so long, and changed so little, shows they’re a good idea.

However, not all padlocks are created equal, and they can cost anything from a few pounds to over £1,000. The difference is largely in the materials used and the overall strength of the lock.

When you buy a padlock, it’s a good idea to make sure the manufacturer has had the lock independently tested. It should come with a CEN (Central European Norm) grade, which refers to the overall strength of the lock – from grade 1 (low security) to grade 6 (maximum security). We recommend choosing at least grade 3 or above.

Let’s take a closer look at the anatomy of a padlock:

Anatomy of a padlock

  • Shackle/Shank

    This is the U-shaped piece of metal that forms the lock. It’s usually made of stainless steel, although stronger materials like boron and solid steel increase the security.

    The shackle is the main point of attack for thieves, so it needs to be strong enough to resist bolt cutters and hacksaws.

  • Locking bar This is a spring-loaded bar of metal embedded in the solid body, which slots into the shackle when the padlock is closed to secure it.
  • Solid padlock body This is the chunky body of the padlock, usually made of solid brass, which houses the locking mechanism and locking bar.
  • Locking mechanism

    The mechanism is usually a tumbler lock, made up of small cylinders and pin tumblers that engage with a key of a certain shape – and only that key. Unlike older styles of lock, tumbler locks are very difficult to pick without specialised tools.

    Fun fact – Linus Yale, who patented the well-known Yale lock in the 1850s, based his designs on a locking mechanism used in ancient Egypt!

  • Barrel/Cylinder This is the part of the lock the key fits into.

Types of padlock

Although the classic brass padlock is cheap and easily available, you may wish to consider some of these alternatives if you want additional peace of mind.

Closed shackle

This type of padlock has high, guarded sides that protect the shackle from cutting and sawing. Insurers may specify the closed shackle, or an equivalent design, as a security measure for protecting valuables.

While very difficult to get into, this design can make it more difficult to fit the lock through a hole, so it’s a good idea to check the full dimensions of the padlock are suitable for your needs.

Straight shackle

Also known as shutter padlocks, these are another common design that guards the shackle. They’re often used in industrial settings, such as securing shipping containers, and may be easier to fit than the closed shackle type.

Round shackle

Another variation on the guarded shackle design, round shackle or disc padlocks are circular in shape, but otherwise work just like an ordinary padlock. They provide additional security as the keyway is in the centre of the lock, which makes them resistant to drilling and forcing. However, make sure you choose a sturdy one – cheap locks are often flimsy locks.

Long shackle

These have an elongated shackle, which is useful if you need to fit the lock through multiple holes arranged in a straight line. However, bear in mind that the shackle is the weakest point of a padlock, so these provide a larger surface area for attack – it may be better to fit multiple individual padlocks instead.

Combination padlocks

Combination locks are opened by a code, rather than a key. This can be convenient in a number of ways: you can provide other people with the code if they need access to your storage unit, and you don’t need to worry about losing your key as long as you have the combination memorised.

Safe dial combination lock

Usually circular in shape, safe dial locks offer many more code variations than the typical four-number combination lock, but otherwise work in much the same way.

At Space Station, we take security very seriously – and you’ll find high-quality graded padlocks for sale at many of our self storage facilities. If you need any help choosing a padlock, just ask and our staff will be happy to help!