A Locksmith's Guide: What Is a "Gourd Hole" (Euro Profile) Lock Cylinder?
Created on 12.04
A Locksmith's Guide: What Is a "Gourd Hole" (Euro Profile) Lock Cylinder?
If you've ever heard a contractor or a hardware supplier talk about a "gourd hole lock cylinder," you probably nodded along while having no idea what they meant. It's a perfect description for the shape, but let's be clear: 'gourd hole' isn't the professional term. As a locksmith, my job is to cut through the jargon.
That "gourd hole" is simply the cutout for the single most common lock standard in the world: the Euro Profile Cylinder.
In this guide, I'm going to demystify this critical part. We'll cover its real name, why it's on almost every door outside of North America, how to measure it (this is the part everyone gets wrong), and what security features you must have.
Terminology 101: "Gourd Hole" is a Euro Profile Cylinder
First things first: "Gourd hole" isn't the lock. It's the shape of the hole in the door. It's that keyhole-shaped cutout the cylinder slides into.
The real, professional name for the part you put your key in is the Euro Profile Cylinder. That's it.
This design was standardized in Germany (you might see DIN 18252 on spec sheets) and it just... took over. You'll find it all across Europe, Asia, Africa, and Australia. While we use different systems in North America (like deadbolts), the Euro cylinder is the global king for doors with mortise or multi-point locks.
So, when you hear gourd hole lock cylinder, just think Euro Profile Cylinder. Same thing.
Why is This Such a Popular Standard? The 3 Key Benefits
So, why this design? Why is it everywhere? It wasn't an accident. The Euro Profile Cylinder is a genius piece of design because it's incredibly practical. It all comes down to three huge wins for you, the property owner.
- 1. Modularity:This is the big one. Your key is lost? Your lock feels gritty? You don't replace the whole handle and mechanism. You just swap the cylinder. It's a five-minute job. That saves you time, money, and a massive headache.
- 2. Flexibility:The Euro standard is a platform. Because the shape is consistent, manufacturers can make a cylinder for every possible need. This includes:
- Double Euro Cylinder:A keyhole on both sides. This is the standard.
- Single-Sided Euro Cylinder:Also called a "half euro." Key on one side, blank on the other. Perfect for storage rooms.
- Euro Cylinder with Thumbturn:Key on the outside, a simple knob on the inside. This one's my top recommendation for fire safety on exit doors. You don't want to be hunting for a key in an emergency.
- 3. Security (Upgradability):This is the best part. Because it's modular, upgrading your security is as simple as changing the cylinder. A new, high-security lock cylinder with better tech comes out? You can swap it in minutes. This is huge. It means you're never locked into old, vulnerable technology.
The 2 Critical Measurements You MUST Know Before Buying
Okay, pay attention. This is the part you absolutely cannot mess up. This is the single most important measurement.
If you get this wrong, your new lock will either not fit or—far worse—it will make your door less secure. The number one mistake I see is someone buying a "70mm" cylinder just because their old one was 70mm total. This is wrong. A 70mm cylinder can be a 35/35, a 30/40, or a 25/45. That "split" is the only thing that matters.
A Euro Profile Cylinder is held in by one retaining screw through the edge of the door. Therefore, all measurements start from this central screw hole.
You need two measurements. That's it.
- Measurement A (The 'Outside' Size):The distance from the center of the retaining screw hole to the outside face of the cylinder.
- Measurement B (The 'Inside' Size):The distance from the center of the retaining screw hole to the inside face of the cylinder.
Your final measurement will be something like "30mm / 40mm" or "45mm / 45mm." It's standard to list the 'A' (outside) measurement first. Getting the 'A' and 'B' measurements correct is critical, and this clear video on how to measure a Euro cylinder provides a perfect visual guide.
Why am I so obsessed with this? Because if your cylinder is too long on the outside, it sticks out. That exposed bit is a giant "welcome" sign for a burglar. They can grab it with a tool and snap the lock in seconds. A correctly measured cylinder sits perfectly flush with your handle. No grip, no entry.
Security Features to Demand in Your Next Cylinder
Don't be cheap here. A $10 cylinder from a discount bin is not the same as a $70 high-security lock cylinder. They might look the same, but one is a real deterrent and the other is just for show.
When you're buying a replacement for an outside door, you must demand these features. No excuses.
- Anti-Snap (The #1 Priority):This is it. This is the whole game. A standard cylinder is weakest right under the screw hole. Thieves know this. An anti-snap lock cylinder is designed with a "sacrificial" cut. If a thief tries to snap it, only the front bit breaks off, leaving the lock itself completely secure and the door still locked. The "snapping" of a cylinder is one of the most common forms of forced entry, a technique that locksmith associations often warn about
- Anti-Drill:Simple. Crooks try to drill out the pins. High-security cylinders have hardened steel pins and plates inside. The drill bit hits them and just spins. End of story.
- Anti-Pick:Lock picking isn't just in movies. Basic locks are shockingly easy to pick. Quality cylinders use special "security pins" (like spool pins, serrated pins, or mushroom pins) that are designed to fool a pick and give false feedback. It's a nightmare for them, which is what you want.
Choosing a High-Quality Gourd Hole Lock Cylinder
Look for cylinders with certifications. You'll often see ratings like the TS 007 3-star (common in the UK) or SKG 3-star (common in the Netherlands). These stamps mean the lock has actually been tested against these attacks, not just marketed with buzzwords.
Seriously, don't just grab the cheapest one. This tiny piece of metal is the only thing between your home and the outside world. Spending a little more here is the single most cost-effective security upgrade you can make.
Once you have your correct measurements, the next step is to choose a high-quality, high-security cylinder, as this is the core of your door's security. You can explore a wide range of premium Euro profile cylinders and compatible locksets designed for modern security and durability.
How to Replace Your Cylinder in 3 Simple Steps
Here's the good news. Once you have the right cylinder, swapping it is incredibly easy. You just need a screwdriver. Here's how you do it in 3 steps.
- Step 1: Remove the Retaining Screw.Open your door and look at the metal edge. You'll see one screw that lines up with the bottom of your cylinder. That's the one. Take it all the way out.
- Step 2: Turn the Key and Pull.This is the trick that gets everyone. The cylinder won't just pull out. You have to put the key in and turn it slightly (about 10-15 degrees). This pulls the "cam" (the black moving part in the middle) in line with the cylinder body. Keep the key turned and pull. It'll slide right out.
- Step 3: Insert the New Cylinder.Do the same thing with the new cylinder. Put the key in, turn it to retract the cam, and slide it into the 'gourd hole.' Wiggle it until the screw hole lines up, then put the retaining screw back in. Make it snug, but don't overtighten it. Test the key from both sides before you close the door!
Pro-Tip: When measuring, always measure from the center of the retaining screw hole to each end (e.g., 'A' = 30mm, 'B' = 40mm). Never just buy one based on the total length (70mm), or it won't sit flush with your handles, creating a major security risk.
Your Gourd Hole Lock Cylinder: The Core of Your Home Security
So, that mysterious "gourd hole lock cylinder" isn't so mysterious after all. It's just the cutout for a standard Euro Profile Cylinder.
Now you know what to call it, how to measure it (from the center screw!), and exactly what security features to look for. Get this one, small component right, and you've just made your home worlds safer.
Frequently Asked Questions about Euro Profile Cylinders (FAQ)
1. What is the difference between a double euro cylinder and a single-sided euro cylinder?
A double euro has a keyhole on both sides. A single-sided euro (or 'half euro') has a keyhole on one side and a blank face on the other. You use single cylinders for doors you only lock from one side, like a closet or a garage side door.
2. What about a thumbturn cylinder? Is it secure?
I love thumbturns. They have a keyhole on the outside and a simple knob on the inside. In a fire, you just twist and go—no searching for keys. The security is all on the outside (the anti-snap, anti-drill part). The only time I don't recommend one is if you have a big glass panel right next to the lock. A thief could break the glass, reach in, and turn the knob. Use common sense.
3. My key won't come out when I'm pulling the cylinder! What am I doing wrong?
You've turned the key too far or not far enough. The cam (the black central part) must be perfectly aligned with the cylinder body. Put the key in, turn it about 10-15 degrees, and pull gently. If it doesn't come, turn it a tiny bit more or less. You'll feel it 'click' into the right spot.
4. What does DIN 18252 mean?
That's the German industrial standard that first defined the size and shape of the profile cylinder. It's the technical sheet that ensures a cylinder from any brand will fit in a lock case from any other brand.
5. Can I use a 'gourd hole lock cylinder' in the United States?
Yes, but it's not the standard for most houses. In the US, we mostly use deadbolts. You will see Euro cylinders on high-end patio doors or modern multi-point locking systems, but they aren't the default.
6. My cylinder sticks out 10mm from the handle. Is that a big deal?
Yes. Fix this immediately. That 10mm is a lever. It's what a burglar uses to grip and snap the lock. Your cylinder face should be as flush as possible with your handle. No more than 3mm sticking out, max. Anything else is a serious security risk.
7. What is an 'offset' cylinder?
"Offset" just means the 'A' and 'B' measurements aren't the same. A 30mm/40mm cylinder is 'offset.' A 35mm/35mm cylinder is 'equal.' Because of door and handle thickness, most doors will need an offset cylinder.
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