Unbeknownst to many homeowners, the Euro Cylinder lock has a rich, interesting history dating back to the 19th century when it was first patented under the “pin tumbler” name. Between then and now, there have been many iterations of the lock and with uPVC doors really taking off in the 1980s, we see them installed in front doors more than ever. This is partially because Euro Cylinders are a convenient size and can be replaced easily – but more on that later. Right now, we’re going to show you how to measure the popular Euro Cylinder lock, so taking it out and replacing it will be a doddle.
Filling in the blanks: Everything you should know about the Euro Cylinder lock
Before we get into the meat of this article, there are a few things you really ought to know about Euro Cylinders from how they work and whether anybody can go about measuring and replacing them.
What are they?
As we mentioned just a moment ago, Euro Cylinders were once known as “pin tumbler locks”. They’ve been around since 1844 and do a grand job of securing your home’s entry points, being particularly suited to uPVC front doors. This is in part because they’re fairly simple to maintain and replace (experienced locksmiths can tackle the job in 5 minutes), and you can do so without removing all of the fittings. They also provide a high level of security when conforming to British Standard 3621.
Much like other types of door locks (mortice deadlocks, for example), they come in a variety of different models. Here are the main ones:
- Half Euro Cylinders – a shorter model, designed for situations where key access is only necessary on one side such as garage doors.
- Double Euro Cylinders – named after the double-keyed feature, this variety can be locked and unlocked on both sides, allowing for greater security.
- Thumb-turn Euro Cylinders – these models have a “thumb turn” mechanism on the inside, enabling swift and easy opening in emergencies. All you have to do is press the thumb turn and the lock is released.
Euro Cylinders can be keyed alike, meaning that multiple locks can be accessed with the same key. Some homeowners enjoy the convenience of being able to open back and front doors with only the one key.
How do they work?
Euro Cylinders are one of the most secure front door locks, owing to their clever design. The “cylinder” part of the name refers to the sideways profile of the lock – a long, cylindrical barrel containing up to 15 pins that press up against the edge of the serrated key when inserted.
To open the lock, you need to insert the correct key, which will line up properly against the pins and apply pressure at the right points. This causes the pins to pop up, allowing an internal plug to rotate, and the lock to open.
How do they compare to other lock types?
Euro Cylinders are increasingly popular on modern properties for all the reasons we’ve already covered, but how do they compare to other lock types? Well, they beat a lot of the competition such as an unreinforced spring latch or smart lock, which might not be insurable in the event of a break-in. However, some of them don’t quite live up to the robustness of mortice locks or multi-point locks.
In fact, they’ve been known to cause issues when the uPVC lock mechanism hasn’t been properly looked after. This might involve the lock itself snapping, the mechanism sticking or the lock becoming misaligned due to the door’s uPVC body warping in the heat.
These issues can be sidestepped with the right precautions though. You’ll need to invest in a Cylinder lock that is manufactured by a trusted name within the industry and ensure that it’s fitted with anti-snap and anti-pick features. Still feeling wary? Then you can combine the Cylinder with an accompanying deadlock or deadbolt to further reinforce your entryways.
Can anyone replace a Euro Cylinder?
There are a handful of reasons why you might want to replace a Euro Cylinder: a faulty lock, maybe your home has been broken into, or perhaps you’re a landlord changing the locks after an unscrupulous tenant has vacated the property. Whatever the case, it’s a relief to know that any competent DIYer can get the job done – just know that you’ll need a few tools.
That said, if you want to ensure a high-quality installation, it’s always best to seek out the help of an expert. To learn more about how much it will cost to get a Euro Cylinder lock fitted check out our price guide.
How to measure a Euro Cylinder lock
With all the contextual information covered, let’s finally cut to the chase. Here are two straightforward methods for measuring your Euro Cylinder lock.
For both, it’s important to remember that some have internal vs external sides – namely, thumb turn varieties – so if you’re measuring one with non-reversible sides, don’t forget to note down which measurement correlates to the internal side and vice versa.
After all, it’s absolutely crucial you get the measurements accurate for your door. If too long or too short, the lock might pose difficulties when used and can be more vulnerable to all sorts of manipulation.
Method 1: Measuring within the door
Measuring your Euro Cylinder within the door is as simple as using a tape measure and placing it from the centre screw hole to the outer edges, AKA the backplates. The two lengths you measure here combined will equal the overall length of the cylinder. Just make sure to keep your measuring tape straight and double-check those numbers if in doubt.
Method 2: Removing the barrel from the door
This method is just as easy as the first, but it takes a tiny bit more effort. Begin by removing the lock from the door; you can do this by locating the fixing screw and then loosening it with a screwdriver, turning anticlockwise until the screw pops out.
Be careful not to simply yank the cylinder when you see that it’s slackened – the design of the lock has the mechanism to keep the barrel in place. Thus, you’ll need to insert the key and turn it ever so slightly for the internal part to properly align and allow for the cylinder to come free. At this stage, you can gently slide it out.
With the Euro Cylinder removed, you can measure it. As you would with the lock still in the door, measure from the very edge of the barrel to the centre screw hole and write down each measurement for each side. More often than not, the front part of the cylinder will be longer than the back part.
Thumbscrew locks
For thumbscrew varieties, you’ll need to be extra careful to acquire accurate measurements. To be successful, avoid measuring the turn part and make sure you only go as far as the tip of the barrel with your tape measure.
Euro Cylinder lock sizes
As has become clear, there are many different sizes of Euro Cylinders, increasing in increments of 5mm. While the size will completely depend on the thickness of your door, the most popular length in the UK is between 60mm and 120mm. To demonstrate the standard sizes, have this size chart.
| External side length | Internal side length | Total length |
| 30mm | 30mm | 60mm |
| 30mm | 40mm | 70mm |
| 30mm | 45mm | 75mm |
| 30mm | 50mm | 80mm |
| 40mm | 40mm | 80mm |
| 40mm | 50mm | 90mm |
| 40mm | 60mm | 100mm |
| 45mm | 45mm | 90mm |
| 45mm | 50mm | 95mm |
| 45mm | 65mm | 110mm |
| 50mm | 50mm | 100mm |
| 55mm | 35mm | 90mm |
| 55mm | 45mm | 110mm |
How to fit your new Euro Cylinder Lock
Step 1: Remove the old lock you’re replacing
To remove the lock from the door, start by locating the fixing screw and loosening it with a screwdriver. Turn the screw anticlockwise until it pops out. When the screw is loosened, don’t just pull the cylinder out – remember, the lock design (specifically the internal cam) keeps the barrel in place. You’ll need to insert the key and turn it slightly to align the internal parts and release the cylinder. Finally, you can gently slide it out.
Top tip: if you’re really struggling to get a tight screw out, instead of risking damaging it by turning it to death with the head of a screwdriver, try using an impact driver. You might have to borrow one, but it’s well worth it!
Step 2: Order a new lock of the right size
Following one of the tutorials above, measure the size of the lock as accurately as you can. If it doesn’t match any of the sizes listed in the chart from earlier, you might want to round it to the nearest 5mm increment. With this information, you can order a new lock to fit.
Step 3: Secure the new lock in place
Doing the exact reverse of the first step, you can fit the new lock. Like your old one, there’ll be cam in the centre that you will need to align so that it’s flush with the door. With that aligned, you can slide the barrel into the door and push it through.
To know whether it’s in the right place on the other side involves feeling it out. When you put your new screw into the centre hole, you should be able to give it a wiggle and feel the hole in the lock align. When you’ve got the screw in there, tighten it a bit and then see if you can still turn the key with it in place. Happy that the mechanism is operating fine? You can then proceed with your screwdriver, tightening the screw until the barrel is secured.
Step 4: Inspect your work and make any adjustments
When inspecting your new lock, it’s important to know that it should slightly protrude on both sides and sit snugly – if the barrel is sliding back and forth, you have a problem, and it needs to be tightened.
Finding the best Euro Cylinder lock
As we’ve mentioned, poor-quality Cylinders are prone to a bunch of issues from lock snapping to their ease of picking. So, what separates these less-than-ideal models from the best products on the market?
Ratings and certification
On top of checking customer reviews, looking at whether the lock in question has met defined industry standards can help you reduce the risk of your locks being compromised. This will ensure that the model you choose has been rigorously tested against cylinder snapping and lock manipulation efforts.
There are two national standards for Cylinders specifically. These are:
- TS 007 (1 star or 3 star)
- Sold Secure Diamond Standard for lock cylinders (SS312)
According to guidance from the West Yorkshire Police, if you are to upgrade your Euro Cylinder locks, they should hit at least one of the above. Plus, you should ensure that the door itself is secure and that you haven’t missed the opportunity to check that the handle is also functional. If not, you’ll be happy to know that door handles can likewise be tested to TS 007 standards, achieving a 2 star rating.
Additional security features
As well as selecting a lock that meets the exacting industry requirements, you can also fit out your door with additional security measures that level up your protection against force and product failure.
For one, you could install sash jammers to the door, which have been proven to reduce the risk of burglary. Or you could opt for a higher-end Euro Cylinder with a combination of features that make lock anti-drill, anti-bump and pick-resistant.
Nowadays, manufacturers will even add a sacrificial cut to their locks to protect against lock snapping: as thieves target your home, forcing the external end of the cylinder, a chunk of it will break away leaving the remaining part fully intact. The best part is that even if that part is removed the lock remains fully functional.
More guides and tutorials to help you out
That’s everything on how to measure a Cylinder lock. We hope we’ve provided you with enough information to make an informed decision about whether going down the DIY or professional route is for you.
Either way, know that we’ve got plenty more on our blog to inspire and empower you. With the right know-how, protecting your property is easier than you think.
