You have probably seen it. The heroic protagonist of a spy movie approaches a locked door, the only thing standing in his way between mission success and fatalistic catastrophe is a pesky hotel lock or door knob set. Luckily for Mr Bond, he’s brought his trusty credit card! Our hero whips out his credit card, slides it into the edge of the door and BOOM he’s inside in 10 seconds. One step closer to completing his mission and romancing a beautiful woman on a beach somewhere. Good work Mr Bond, you nailed it. The question is though, is that reality?

Does it work?

Short answer, YES….. BUT! (there’s always a but) The only reason this technique works in real life is incompetent lock fitting by someone who is either not a qualified locksmith or is a bad locksmith. The technique to open locks this way is called “shimming” and has been practised by locksmiths, governments, criminals, fire fighters and security specialists for a long time, probably a longer time than I have been alive to be honest. Shimming works because any lock that is self latching has an angled steel tongue that protrudes out the edge of the door and into the door frame. This latch has to be spring loaded or else the door wouldn’t close, and luckily for locksmiths and opportunistic thieves, springs are operated by PRESSURE. We slide our Shim into the edge of the door which results in end pressure on our bevelled latch and there we have it, latch retracts into the door and hey presto the door is open.

(examples of some shimming tools used by locksmiths)

What can you do about it?

Customers of mine are not thrilled when they pay after hours locksmith fees for me to turn up and use a 5c piece of plastic to gain entry to their home, and they should be upset. As I mentioned earlier this is only possible because your locks have been fitted incorrectly. The security industry constantly updates and changes its hardware and electronics to thwart any known exploits of their products, after all it is a multi-billion dollar industry. So you would think they’ve engineered something to prevent these simple attacks, well……..they have. Its called a “dead latching pin” and I wont go into the boring ins and outs of it but what you need to know is this, the word “dead” in locksmithing essentially means “not spring loaded”. When your locks are fitted correctly and aligned with the strike plate as per manufacture’s specifications the dead latching pin is engaged and the lock can no longer be shimmed. Most of you reading this would already have a lock with a dead latching pin on your door, but it just doesn’t work properly! This is because when your house was built or lock replaced, the person installing it had not been properly trained, as simple as that. The scary part is that about 7 out of 10 locks I see in the field are not installed correctly and therefore susceptible to be shimmed by Joe Blow (and myself) with a piece of plastic.


There are other advanced shimming techniques one can use to work around this pesky dead latching pin issue like spreading, hooking or bypassing. But I wont get into those subjects today as they aren’t such an immediate issue. Bad guys go for the quick and easy. So to summarise, have your locks installed professionally and if you’re locked out of your home and its just your door knob locked, give it a go! I would recommend not using a credit card but an ID card of some sort with no raised numbers or bevels on it. Might save you $200, but you might also snap your card so I won’t take any responsibility for broken ID’s! 😊 Locksmiths use materials specifically designed to shim locks but I have also used my drivers license in a pinch.


Thanks for reading and stay safe!


SK Locksmiths provide free onsite quotes and security consultations for residential, commercial and industrial security needs. We are local Brisbane Locksmiths who are passionate about our work and strive to excel in providing customers the best service possible.