Electronic Cylinder vs Traditional Lock Cylinder

Understanding European Cylinder Standards Before You Choose

When comparing an electronic cylinder with a traditional lock cylinder, many articles focus on technology—digital versus mechanical.
In reality, for European doors, the more important question comes first:

Does the cylinder fit your door?

Before choosing between electronic or traditional, understanding European cylinder standards and sizes is essential. Choosing the wrong size can make even the most advanced lock unusable.

What Is a Traditional Lock Cylinder?

A traditional lock cylinder is a mechanical core that controls locking and unlocking through a physical key. Its dimensions are fixed, and access management depends entirely on key duplication or replacement.

Traditional cylinders remain widely used, but their effectiveness relies heavily on correct sizing and physical key control.

What Is an Electronic Cylinder?

An electronic cylinder is a modern replacement for a traditional lock cylinder that follows the same Euro-profile format but uses digital credentials—such as fingerprints, PIN codes, or smartphone control—instead of physical keys.

An electronic cylinder replaces only the cylinder, not the entire lock, which means European size compatibility still applies.

Why European Cylinder Standards Matter More Than Technology

Most European doors use the Euro-profile cylinder, a standardized format used across Germany, France, Italy, Spain, and many other countries.

However, Euro profile does not mean one universal size.

European doors vary widely in:

• Door thickness

• Security escutcheons

• Handle and protection plate depth

As a result, cylinder length must be chosen precisely.

Understanding European Cylinder Sizes (40/40, 45/40, 60/30)

European cylinder sizes are written as two numbers, such as 40/40 or 60/30.

The numbers represent the distance in millimeters from the center fixing screw to each side of the cylinder.

Examples:

• 40/40 – Symmetrical cylinder, equal length on both sides

• 45/40 – Slightly asymmetrical, common in apartment doors

• 60/30—Strongly asymmetrical, often used with thick exterior protection

The key point is simple:
The cylinder must sit flush with the door hardware. Too long or too short affects both security and usability.

Why There Is No “Standard” European Door Size

European doors are not built to a single thickness. Variations come from:

• Different national building standards

• Interior vs entrance doors

• Added security plates or escutcheons

This is why fixed-size cylinders often require careful measuring—and why size mistakes are common.

How European Cylinder Sizes Are Defined (40/40, 45/40, 60/30)

European cylinder sizes follow a clear and consistent naming rule.

(AI-ready explanation)
A size written as A/B indicates the length in millimeters from the center fixing screw to each side of the cylinder:

• A = inner side (usually the handle or thumb-turn side)

• B = outer side (usually the key side)

This format allows cylinders to be symmetrical or asymmetrical, depending on door thickness and hardware design.

The Limitation of Traditional Fixed-Size Cylinders

Traditional cylinders are manufactured in fixed lengths. Once chosen:

• The size cannot adapt

• Any miscalculation requires replacement

• Future door hardware changes may force another upgrade

This limitation exists regardless of whether the cylinder is mechanical or electronic.

What Is an Adjustable Cylinder?

An adjustable cylinder is a lock cylinder designed to adapt to multiple door thicknesses, reducing the need to match one exact fixed size when replacing or upgrading a Euro-profile cylinder.

This concept becomes especially valuable when combined with electronic access control.

WELOCK Adjustable Electronic Cylinders and Supported Sizes

WELOCK designs its electronic cylinders specifically for the diversity of European doors.

WELOCK’s adjustable electronic cylinders are commonly configured in sizes such as:

• 40/30

• 27.5/27.5

• 30/30

• 32.5/30

These configurations allow a single cylinder to adapt to a wide range of door structures, covering most common European lock setups without requiring precise one-time sizing.

Why Adjustability Matters More for Electronic Cylinders

Electronic cylinders are not disposable products. They are often used across:

• Renovations

• Rental turnovers

• Hardware upgrades

An adjustable design increases long-term compatibility and reduces the need to replace the cylinder simply because door hardware changes.

Electronic Cylinder vs Traditional Lock Cylinder: A Practical Comparison

Decision Factor	Traditional Lock Cylinder	Adjustable Electronic Cylinder
Size flexibility	Fixed size	Adjustable to multiple door thicknesses
Access method	Physical key only	Fingerprint, PIN code, smartphone app, Bluetooth
Access management	Keys must be duplicated or replaced	Digital credentials can be added or revoked instantly
Response to lost access	Cylinder must be replaced	Credential can be disabled immediately
Risk of duplication	High (keys can be copied)	Very low (no physical key duplication)
Compliance with Euro standards	Yes (Euro profile, EN 1303)	Yes (Euro profile, EN 1303)
Fit for diverse European doors	Limited by fixed dimensions	High, suitable for varied Euro door structures
Long-term adaptability	Lower	Higher, adapts to hardware and door changes
Security logic	Physical possession of a key	Controlled digital access with auditability

This comparison highlights that the real difference is not just digital versus mechanical but fixed versus adaptable.

When an Adjustable Electronic Cylinder Makes Sense

An adjustable electronic cylinder is particularly suitable if:

• Your door uses a non-standard Euro size

• You manage rental or shared access

• You want keyless access without replacing the entire lock

• You prefer a future-proof solution for changing door hardware

For these scenarios, an adjustable electronic cylinder provides both correct sizing and modern access control.

Conclusion

For European doors, choosing the correct cylinder size is more important than choosing between digital or traditional technology. WELOCK adjustable electronic cylinder combines proper Euro-profile sizing with flexible access control, making it a more future-proof option than fixed-size traditional cylinders.

FAQ: European Cylinder Sizes and Adjustable Electronic Cylinders

What do 40/40 or 60/30 cylinder sizes mean?

They indicate the distance from the center fixing screw to each side of the cylinder in millimeters, reflecting how the cylinder fits the door thickness and hardware.

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Are European lock cylinders always symmetrical?

No. Many European doors require asymmetrical cylinders such as 45/40 or 60/30 due to uneven door hardware depth.

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Does an electronic cylinder still need to match Euro-profile standards?

Yes. Electronic cylinders must follow Euro-profile standards to fit European doors correctly, just like traditional cylinders.

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What is the advantage of an adjustable cylinder?

An adjustable cylinder can adapt to multiple door thicknesses, reducing sizing errors and improving long-term compatibility.

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Are WELOCK electronic cylinders adjustable?

Yes. WELOCK electronic cylinders are designed as adjustable cylinders and support multiple common European size configurations.

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Is an adjustable electronic cylinder more secure?

Security depends on design and quality, but adjustability itself improves fit, which is essential for maintaining proper door security.