What is a British Standard 3621 Lock?

British Standard

As locksmiths in London specialising in door locks repair services we are well versed in British Standard locks requirements and locks required for insurance purposes. So what are British Standard locks?

What Does British Standard Locks Mean?

The British Standards Institution (bsi.) carry out product testing on security products including windows, doors and locks. British and European standards must be met for a product to be awarded certification and the British Standard Kitemark and CE marking. 

What Does BS3621 Mean?

BS 3621 relates to certification of “Thief resistant lock assembly. Key egress“. Key egress means that when locked a key is required to exit the door. For example a 5 lever deadlock for wooden door security. Commonly known as a Chubb lock.

BS 3621 5 lever deadlock

Insurance Approved BS8621 Locks For UPVC Doors

BS8621 relates to “Thief resistant lock assembly. Keyless egress“. Keyless egress means the lock may be locked from the outside but can be exited from the inside without the use of a key. For example, 3 star British Standard anti snap locks used on UPVC doors.

3 star BS3821 lock

Not only is the product quality and specification assessed but the means of fitting the lock is also specified by British Standards. This is why it is important to choose a locksmith experienced in insurance approved lock fitting.

Insurance Approved Door Locks Fitting

If you check your home contents policy you will find that they specify the use of insurance approved locks to meet British Standards. This means using the correct British Standard locks and professional installation. The method of fitting the lock must meet British Standards.

When choosing a door lock replacement service in North London or anywhere in the UK it is important to choose a trained, experienced specialist locksmith. Not all locksmiths have the knowledge required to fit a deadlock to British Standard.

MLA approved Locksmith

Features of a British Standard 3621 Lock

A lock bearing the BS3621 kitemark will have particular features which increase security when installed to standard by a professional.

  • It can be deadlocked and the key taken away from both sides.
  • It prevents access or exit through the door without the use of a key.
  • The case and the bolt are resistant to drilling with standard tools for at least 5 minutes.
  • It has a mechanism that prevents tampering (picking).
  • The bolt must project into a steel keep by 20mm at least.
  • The locking bolt can take a sideways force of up to 10kg.
  • There should be at least 1000 different key cuts for the lock type before a key is repeated.

It is these features that provide high security and insurance approval.

insurance approved deadlock

The Advantages of BS3621 Standard Locks

As a property owner, choosing a BS3621 five lever mortice deadlock has a number of advantages. A branded lock that meets British safety standards ,such as a Union door lock (previously know as a Chubb door lock), will be much more resistant to intruders.

A good 5 lever mortice deadlock will prevent a range of methods of gaining access such as;

  • Reaching in to open the door from inside.
  • Destructive entry
  • Lock picking
  • Forced entry

It also decreases the likelihood of other property owners having duplicate keys in the same area.

The Best High Security Locks for Wooden Doors

BS3621 locks are without a doubt the best high security locks for wooden doors available. It is vital to choose a high quality branded lock fitted by an experienced locksmith. If you are unsure if your locks are insurance approved and if they meet the latest British Standard contact us to carry out a free security survey.

IKS Locksmiths are specialists in door and windows security locks installation at highly competitive prices. Contact us for all your security needs.

How can we help you?

For professional security advice and information call to speak directly to Martin, our Master Locksmith and security specialist.

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Master Locksmiths Association

Master Locksmiths Association



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