How to Get a Snapped Key Out of a Lock

Why Keys Snap in Locks

Snapping a key inside a lock is a frustratingly common problem, particularly in the UK where temperature changes and damp conditions accelerate wear on both keys and lock mechanisms. Keys snap most often due to:

• Metal fatigue - Repeated use over years gradually weakens the key at stress points
• Worn or stiff locks - Forcing a key in a lock that needs lubricating puts excessive strain on the blade
• Damaged keys - Bent or previously repaired keys are significantly weaker
• Cheap key copies - Poor-quality duplicate keys are more prone to snapping

Understanding the cause helps you prevent it happening again once the immediate problem is resolved.

Types of Locks Commonly Affected in the UK

Yale (Pin Tumbler) Locks

The most common lock on residential front doors. The key blade is relatively thin and can snap if the lock is stiff or the key is worn. These are generally easier to deal with because the broken piece is often close to the keyway entrance.

Mortice Locks

Found on many internal doors and older timber front doors. The key is thicker and less prone to snapping, but if it does break, the fragment may be deeper inside the mechanism.

Euro Cylinder Locks

Found in uPVC and composite doors. These can be particularly challenging because the keyway is narrow and the broken key may be lodged firmly inside the cylinder.

Safety Precautions Before You Start

Gather the following before attempting extraction:

• Narrow-tipped tweezers
• Flat-head screwdriver (very small)
• Broken key extractor kit (available from hardware shops, around £5-£10)
• Lubricant - WD-40 or silicone spray
• Safety glasses and gloves

Never attempt extraction with fingers alone - broken key edges can be sharp, and pushing the key further in makes extraction harder.

Assessing the Situation

Before choosing a method, assess:

1. How deep is the broken fragment? If part of the key is still visible or protruding from the keyway, extraction is more straightforward. If it is flush or recessed, you need a different approach.
2. Is the lock still functional? If the lock cylinder itself is damaged, extraction alone may not restore access.
3. Is the key straight or twisted? A twisted fragment is harder to grip and may require a locksmith’s specialist tools.

Methods for Removing a Snapped Key

Method 1: Tweezers (Key Fragment Partially Visible)

1. Apply a small amount of lubricant to the keyway - this helps the fragment slide
2. Insert narrow-tipped tweezers alongside (not over) the fragment
3. Grip the edge of the broken key firmly
4. Pull gently and steadily - do not twist or jerk
5. If the key moves but does not come free, reapply lubricant and try again

Method 2: Tap and Pull (Key Flush with Keyway)

1. Lubricate the keyway thoroughly
2. Hold the lock with the keyway facing downwards if possible
3. Tap the face of the lock firmly with your palm or a rubber mallet - vibration can shift the fragment slightly
4. Switch back to tweezers and attempt to grip and extract

Method 3: Broken Key Extractor (Deep Fragment)

Broken key extractor tools have a hooked end designed to engage with the key’s serrations:

1. Apply lubricant to the keyway
2. Insert the extractor hook alongside the fragment, serration side facing the key’s cuts
3. Twist gently to engage the hook with the key’s edge
4. Pull steadily outwards while maintaining hook engagement
5. Repeat with small adjustments if the fragment moves but does not come out fully

When to Call a Professional Locksmith

Do not persist if:

• Multiple attempts have failed and the key is moving deeper into the lock
• The lock cylinder feels damaged or is no longer turning
• You do not have appropriate tools and do not want to risk causing damage
• The door is your only means of entry or exit

A professional locksmith carries specialist extraction tools and can remove even deeply lodged fragments without damaging the lock. If the lock is already damaged, they will advise on replacement.

Preventing Snapped Keys in Future

• Inspect keys regularly - Look for bends, cracks, or thinning near the shoulder
• Lubricate locks annually - Apply graphite powder to the keyway and operate the lock a few times
• Replace worn keys before they fail - Getting a spare cut is far cheaper than an emergency locksmith call
• Never force a stiff lock - If the key requires significant effort to turn, the lock needs attention, not more force

Broken Key Extraction in London

City Locksmith London specialises in broken key extraction for all lock types across London. We use professional-grade tools and can usually resolve the problem without any lock damage.