When the Key Won’t Turn

Why a key sticks or will not turn, the safe things to try first, and the signs that mean it is time to stop.

A key that goes in but will not turn is one of the most common lock problems there is. The cause is nearly always dirt in the pin stacks, a key worn too far to lift the pins, a door that has shifted so the bolt presses on the strike, or a worn part inside. Watching what the key and the bolt do usually tells them apart; forcing the key is how a stiff lock ends with a key snapped off in the plug.

Start With What the Key and Bolt Do

Each part of a lock gives its own signs, and two or three signs together often point to one cause.

Have You Noticed Any of These?

Tick every sign that fits the lock.

The key slides in but will not turn It turns, but only with force or jiggling It feels gritty, or got stiff after a dust storm A new copy sticks, or the key is bent or worn smooth It works with the door open, but binds with it shut The key turns all the way, but the bolt does not move The lock is loose, or the cylinder turns with the key Part of a broken key is still in the lock

Tick what you have noticed, then press the button.

In short: a key that will not turn, or turns only with force, usually means grit, a worn key or a bolt rubbing the strike. A bolt that does not move with the key, a loose lock and a broken key should not wait.

Stuck-Key Symptoms and What They Point To

Each sign has a point where trying more at home starts to do harm.

Symptom	Likely cause	What to try	When to stop
Key will not turn at all	Grit in the pins, a worn key, or a bolt pressed on the strike	The spare key, a dry lubricant, a push or pull on the door	Neither key turns, or a key starts to bend
Turns only with force	Dry, dirty pins, or key cuts worn round	A clean, a dry lubricant and the least worn key	It still takes two hands or a tool
Works only with the door open	The door has dropped, so the bolt rubs the strike plate	Lift or push the door while locking; tighten the hinge screws	The bolt cannot slide out fully with the door shut
Key turns, bolt stays put	A broken cam or tailpiece, or a worn bolt	A check that the thumb turn still moves the bolt	As soon as you notice; the door may not lock
Lock or cylinder loose	Loose trim screws, or a cylinder set screw backed out	Tighten the screws on the inside of the lock	It still wobbles, or turns with the key
Broken key in the lock	A worn or cracked key that gave way under force	Nothing in the keyway; keep the other half	Before pliers, glue or the spare go near it

Can summer heat make a deadbolt hard to turn?

The lock changes very little, but the door does. A door in full afternoon sun can move enough for the bolt to rub the strike, so a deadbolt that binds only on hot afternoons points to the door and the strike, not the cylinder.

Why does a new copy of my key stick when the old one works?

A copy can be cut slightly off, or cut from a key that was already worn. Have copies cut from the original or the least worn key; if every key sticks, the cylinder is the problem.

Freeing a Sticking Lock

A lock that is stiff but still turns usually comes back with a careful clean.

Open the door and keep it open, so a bolt that sticks cannot shut you out.
Shine a flashlight into the keyway. Dust is normal; a metal sliver or a piece of key means stopping here.
Blow out loose dust with a short burst of compressed air.
Add a small puff of powdered graphite or a short spray of a dry PTFE lock lubricant.
Work the key in and out five or six times, turning it fully each way, then wipe it clean.
Test the lock with the door open, then shut, from both sides.

Leave oil, grease and general-purpose sprays out of the lock. They loosen it for a week or two, then hold the dust that reaches the keyway; in Phoenix, where fine desert dust gets into every outside lock, they become a paste that packs the pin stacks.

Lock cylinder held between two fingers, its pin stacks packed with grit and corrosion

Is graphite or a dry PTFE spray better for a sticking lock?

Both suit a pin tumbler cylinder. Graphite powder works best in a lock that is already clean; a PTFE spray goes on wet, reaches deeper and dries to a thin film. Use a little of either, and keep both off the buttons of a keypad lock.

Habits That Damage a Sticking Lock

Most harm to a stiff lock is done while forcing it. Leave these out:

Oil, grease or a general-purpose spray in the keyway
Pliers through the bow of the key for more force; the key twists and snaps
Glue on a toothpick to pull out a broken key; it seals the pins
The spare pushed in after a broken key; it drives the piece deeper
Slamming the door to line up the bolt; it bends the strike
Copies cut from copies; each carries the last one’s wear

A Cylinder Worn Past Cleaning

Brass is soft, and years of keys wear it: the keyway edges round off, the pins flatten and metal fragments collect, so the lock grows stiffer however often it is cleaned, and it wears every key that goes in.

Close view of a worn brass cylinder face held in the fingers, its keyway damaged and full of metal fragments

Past that point, the cylinder usually needs rekeying or replacing. A new cylinder can often take the keys you already carry.

If the Key Breaks Off in the Door

Keys rarely break without warning. Most give way at the shoulder after months of forcing a stiff lock, so a cracked or bent key is worth replacing first.

Brass lock cylinder pulled apart between the fingers, the broken half of a key still in the plug

If one breaks, leave the piece where it is and keep the other half, which shows the cuts. A locksmith will normally draw the piece out with thin extractor tools, then find out why the lock was stiff enough to break a key. Call or book a visit, and say whether the door is locked.

If the key still will not turn, call and tell us what the lock does.

(623) 257-5892 Book a Visit