Why is my key hard to turn in the lock?

Start with the key

A key that has gone stiff is most often a dirty or dry lock, a worn or badly copied key, or a door that has shifted. Work through those in that order, because the first two cost nothing.

Try a spare key, ideally the original rather than a copy of a copy. If the spare turns smoothly, the first key is worn or was cut poorly, and a fresh copy from the original usually fixes it. Look at the stiff key too: a bent blade or a burr left from cutting can drag against the pins.

Check whether it is the lock or the door

Turn the key with the door open. If the bolt moves freely when the door is open but binds when it is shut, the lock is fine and the door has shifted so the bolt rubs the strike plate. In that case the key is not the problem and no lubricant will help; a pro can realign the strike.

If the key is stiff even with the door open, the trouble is inside the cylinder.

Clean, then lubricate lightly

Over time, dust, particles and chemicals in the air settle on and in the lock, and they can create friction inside the precision locking and keying components and impede the performance of the lock.^[1] Master Lock's padlock guidance says to use pressurized air to blow all dust out of the keyway, and a can of compressed air does that job on a door lock too.^[1]

Then add a little lubricant. For its own locks, Master Lock recommends a PTFE lock lubricant and says to apply lubricant sparingly: a very light spray or a few drops is all that is needed.^[1] After application, insert the key and open and close the lock several times to distribute the lubricant, then wipe excess lubricant off the lock and key.^[1]

Be careful with graphite and silicone

The advice on graphite differs between makers. Master Lock says never to use dry graphite or a silicone lubricant, because graphite is often applied in excess, which interferes with part movement.^[1][3] Schlage's service manual for its cores mentions graphite as an option when lubricating, but warns that if you use it you should not overdo it, or the springs will not have room to compress properly.^[2] The common point is quantity: a heavy dose of powder or oil in a keyway can clog it and turn a stiff lock into a stuck one.

Avoid cooking-oil sprays and general penetrating oils in a keyway as well. They tend to leave a film that collects dust.

What the fix looks like in order

Once you have ruled out the door, the usual order is a clean spare key, compressed air, a light PTFE lubricant, and a few passes of the key to work it in. If that does not help, the cylinder is probably worn or has a bent or broken pin inside.

Stop and call a pro if

• The key sticks, bends or will not come out. Do not force it. A snapped key in the cylinder needs extraction.
• The key turns only with a wiggle or lift. That points to worn pins or a worn key, and a locksmith can rekey or replace the cylinder; see how to rekey a door lock.
• The lock is on a smart or electronic deadbolt that also seems to bind, or the motor labours. Do not take it apart.
• The bolt rubs the strike when the door closes. That is a door alignment job.

Before you hire, see whether locksmiths need a licence in Virginia. For a price range, read how much a locksmith costs in Virginia. You can also browse other repair answers or handyman services.

When you are ready, describe the lock problem once and local pros quote it.