Key Hard to Turn or Sticking in the Lock? Causes and Fixes

A lock rarely fails without warning. First the key needs a little wiggle, then it has to be pulled out slightly before it turns, then one cold morning it will not turn at all. Catching the problem at the jiggling stage makes it much easier to fix.

Cause 1: A worn key

Keys wear down with use, and a copy made from a worn key copies the wear. Hold your key next to a spare: if the ridges on yours look rounded and shiny while the spare's are sharp, the key is the problem, not the lock.

Cause 2: Dirt and dust inside the lock

Locks collect grit, pocket lint and dust over the years, especially on doors that face the weather. The result is a key that goes in stiffly and turns with a grinding feel.

A lock lubricant made for locks, usually a dry graphite or a dry spray, can help. Apply a small amount into the keyway, then insert and turn the key several times.

Cause 3: Cold weather

Pennsylvania winters are hard on outdoor locks. Moisture inside the cylinder can freeze, and cold makes a stiff lock worse.

• Warm the key in your hand, then insert it gently.
• A lock de-icer from an auto parts store can help on a frozen lock.
• Never pour hot water into a lock. It freezes again, often worse.
• Never force a frozen key. That is exactly how keys break.

Cause 4: The door, not the lock

Sometimes the lock is fine and the trouble is where the bolt meets the frame. Here is a simple test: open the door and turn the key. If it turns easily with the door open but drags with the door closed, the bolt is rubbing against the strike on the frame.

That happens when a door shifts with the seasons or drops slightly over the years. Our guide on a door that won't lock or latch explains what to check next.

What not to do

• Do not use pliers on the key to get more turning force.
• Do not keep jiggling a key that is binding harder each time.
• Do not copy a worn key, because it copies the wear.
• Do not put glue anywhere near a lock or a broken key.

If the key breaks in the lock

Stop, and leave the broken piece where it is. Pushing it deeper or trying to hook it out with a paper clip or a small tool can jam the lock completely. Keep the other half of the key: it shows exactly how it was cut.

Repair or replace?

A lock that sticks from dirt or wear can often be repaired: the worn or damaged part is replaced and the rest of the lock stays on the door. A lock that is loose on the door, badly worn inside, or damaged is usually better replaced. If you are replacing anyway, it is a good moment to decide whether you want a better deadbolt or a keypad model.