Mortise Locks vs. Cylindrical Locks — Commercial Hardware Compared
Two fundamentally different ways to build a commercial door lock — one cut into a pocket in the door edge, one bored straight through. Here's what actually separates them.
Nearly every commercial door lock is built one of two ways: mortised into a pocket cut in the door's edge, or bored straight through the door face and edge. The distinction isn't cosmetic — it affects durability, the range of available functions, and how the lock holds up to heavy daily use. Here's the real comparison.
Quick answer: mortise locks are built into a pocket in the door edge, offer more built-in functions (deadbolt plus latch in one unit, more trim options) and generally hold up better under very heavy daily use. Cylindrical (bored) locks are simpler to install and less expensive, and are the standard choice for most office and retail doors.
How mortise locks are built
A mortise lock body sits inside a rectangular pocket cut into the door's edge, with separate holes for the cylinder and the interior trim. This construction allows a single lock body to combine a deadbolt and a latch in one unit, along with a wider range of trim and function options than a cylindrical lock typically offers. The tradeoff is installation complexity — cutting a proper mortise pocket requires more precise door prep, making it a bigger job on an existing door than swapping in a cylindrical lock.
How cylindrical (bored) locks are built
A cylindrical lock — sometimes called a bored lock — installs through two holes bored into the door: one through the face for the lock body, one through the edge for the latch. This is faster and less expensive to install or replace than a mortise lock, and it's the standard on most office suites, retail entries, and interior commercial doors.
| Factor | Mortise Lock | Cylindrical Lock |
|---|---|---|
| Installation | More complex — requires a precise mortise pocket | Simpler — two bored holes |
| Durability under heavy use | Generally higher | Good, but the more common failure point on very high-traffic doors |
| Function options | Wider range in a single unit | More limited per unit, though still broad across the category |
| Typical use | High-traffic entries, storefronts, institutional buildings | Offices, retail suites, most interior commercial doors |
| Relative cost | Higher | Lower |
Which one is actually right for a given door?
For a standard office suite or interior door with moderate daily traffic, a quality cylindrical lock is usually the practical, cost-effective choice — the extra durability of a mortise lock isn't necessary at that use level. For a main storefront entrance, a heavily trafficked institutional door, or anywhere the lock will be cycled hundreds of times a day for years, a mortise lock's added durability and function flexibility tend to justify the higher upfront cost through fewer service calls and replacements over time.
Retrofitting a door from cylindrical to mortise (or the reverse) is a real, but more involved, door prep job — worth factoring into a renovation or new-door decision rather than treating it as a simple hardware swap after the fact.
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Frequently asked questions
Can I replace a cylindrical lock with a mortise lock on the same door?+
It's possible but involves more door prep than a like-for-like swap, since a proper mortise pocket needs to be cut into the door edge. It's a reasonable option during a renovation or door replacement, but a bigger job than simply swapping one cylindrical lock for another.
Which type is better for a storefront entrance?+
Storefronts with heavy daily foot traffic generally hold up better with mortise hardware, given the higher cycle counts and the wider range of function options mortise locks support. That said, quality cylindrical locks are also commonly and successfully used on storefronts with more moderate traffic.
Are mortise locks harder to rekey than cylindrical locks?+
No — rekeying itself works the same way on both (changing the internal pins), regardless of whether the lock body is mortised or bored into the door. The construction difference affects installation and durability, not the rekeying process.
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