Broken Key Stuck in Your Lock: Why It Happens and What to Do Next

Broken Key Stuck in Your Lock: Why It Happens and What to Do Next

You put your key in the lock, turn it, and snap — half the key is in your hand and the other half is stuck inside the lock. It is one of those moments where you just stand there staring at it, wondering how this is your life right now.

Do not force the remaining key fragment or push another object into the keyway. Extraction and entry depend on the break position, cylinder, door and whether another fault is present. First, here is why keys can break and what not to try before calling.

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Why Keys Snap in Locks

Keys are not invincible. They are made of brass or nickel silver, and over time they weaken. Here are the main reasons keys break:

Cold weather and a stiff mechanism. Metal components can contract in cold conditions and moisture can affect operation. If the lock becomes stiff, forcing a weakened key can cause it to break.

Key material, wear and cutting quality. Key blanks and cuts can differ, but appearance or where a key was cut does not establish its strength or lifespan. Inspect a worn, bent, cracked or poorly operating key and avoid forcing it.

A worn or stiff lock. If your lock has not been maintained — no lubrication, internal parts corroded or gummed up with dirt — it takes more force to turn the key. More force means more stress on the key, and eventually it gives way. This is especially common on older mortice locks and euro cylinders that have never been serviced.

Too much weight on the keyring. This one surprises people, but it is genuine. A heavy keyring pulling on the key while it is in the lock creates lateral stress on the blade. Over months and years, this weakens the key at the point where the blade meets the bow (the handle part). When it finally snaps, it breaks right at that stress point.

A worn key with visible cracks. Take a look at your keys right now. Can you see any hairline cracks, especially near the base of the blade? Is the key visibly thinner than it used to be? Those are warning signs. If a key looks worn, get a new one cut from the original — not from the worn copy.

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What NOT to Do

I cannot stress this enough: most of the things people try before calling me make the situation significantly worse.

Do not insert pliers into the keyway for a flush or recessed fragment. Tools can push the piece deeper or damage internal components. If the fragment does not protrude far enough for a gentle straight pull, stop and arrange an assessment.

Do not use superglue. The glue can run into the mechanism, bond with internal parts and turn a possible extraction into a cylinder replacement. Please do not do this.

Do not try to pick the lock yourself with random tools. Hairpins, paperclips, and screwdrivers are not lock picks. You are more likely to damage the lock mechanism, push the key piece further in, or scratch the inside of the cylinder so badly that even a new key will not work smoothly.

Do not force a second key in. If you have a spare key, do not try to push it into the lock alongside or behind the broken piece. There is no room, and you will jam both pieces in there.

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What You CAN Try (Safely)

If the broken key is protruding from the lock face — meaning you can see the end of the broken piece sticking out — you can try the following:

If it comes out, brilliant. Try your spare key in the lock to make sure everything still works smoothly. If the lock feels rough or stiff, it may need replacing — the break may have damaged the pins inside.

If the key does not come out easily, stop. Do not force it. Call me on 024 7522 4730.

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How I Extract Broken Keys

When I arrive, I assess the situation first. Where is the broken piece? How deep is it? What type of lock is it? This determines the approach.

Specialist extractor tools. Broken-key extractors may allow the fragment to be removed where its position, the keyway and the lock condition make that method suitable. The time and outcome cannot be established from the symptom alone.

Pick and hook method. For keys that are deeper inside the cylinder, I use a combination of a hook pick and an extractor. The hook manipulates the pins to release pressure on the broken key, while the extractor pulls it free.

Cylinder removal. In some cases — particularly if someone has already pushed the key piece deep inside, or if the lock mechanism is damaged — I need to remove the cylinder entirely to extract the key from the back. If replacement is supported, the cylinder dimensions, security specification and current compatible-part availability determine whether it can be completed during that attendance or needs a return visit.

I assess whether a non-destructive extraction is suitable first. The result depends on the break position, lock condition and any earlier attempts to remove the key; if the mechanism is damaged, replacement may be necessary.

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Price Basis

Broken-key extraction needs a job-specific quote because the fragment position, lock type, condition and any earlier removal attempt determine the method. If a compatible euro cylinder also needs replacing, the published replacement price starts from £59 under the scope on the prices page. Mortice-lock and other repair work is quoted after the actual mechanism is identified.

There is no VAT or separate call-out fee. I explain the supported price basis and assumptions before travelling and agree any inspection-led revision before additional work.

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How to Prevent Keys Breaking

Get spare keys cut from the original. Copies of copies degrade. Each generation loses a tiny bit of accuracy and the key blank may be lower quality. Always cut from the original if you can.

Follow the lock manufacturer's maintenance instructions. Use only a lubricant and method approved for the exact product; do not assume one product or interval is suitable for every lock.

Replace visibly worn keys. If a key is thinning, cracked or bent, stop using it and ask a competent key cutter or locksmith to assess a replacement. A worn copy may not be a suitable source for another copy.

Lighten your keyring. Your front door key does not need to share a ring with 15 other keys, a bottle opener, and a torch. The less weight hanging off the key while it is in the lock, the less stress on the blade.

Respond to stiffness without forcing the key. Alignment, contamination, wear and component faults can cause similar symptoms. An assessment may identify a maintenance or repair option, but it cannot guarantee prevention of a later failure or establish a saving in advance.

For more information on maintaining uPVC door hardware, see my guide on uPVC door locks.

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When to Call Me

Call 024 7522 4730 if:

I cover the locations listed across Coventry and Warwickshire — from the city centre to Tile Hill, Canley, Binley, and beyond. Call with the full postcode for the current arrival estimate.

Visit the emergency lockout service page for more details on how emergency call-outs work.