Doors & windows

Fix a sticking deadbolt or door lock

You have to push, pull and jiggle the door just to lock it. A stiff lock feels like it's broken, but most of the time the lock is fine. The bolt just doesn't line up with the hole in the frame, or the mechanism needs the right kind of lubricant.

Written and reviewed by Grab the Hammer Team · Updated Sep 2026
Deadbolt hitting low on the strike plate, with graphite lubricant for the keyway
Why a deadbolt sticks: the bolt hits the strike plate (2) instead of the hole (1). If the lock is stiff even with the door open, puff graphite into the keyway (3).

What's actually going on

A test tells you which problem you have. Open the door and turn the deadbolt. If it moves smoothly with the door open but sticks when closed, it's an alignment problem between the bolt and the strike plate on the frame. If it's stiff even with the door open, the lock itself needs lubrication.

Why it happens

Misalignment

The door sags a little, and the bolt starts hitting the strike plate instead of sliding into the hole.

Dirt in the lock

Dust and grime build up in the pins, especially on exterior doors.

The wrong lubricant

Oil sprays attract dirt and gum up the mechanism over time.

A worn key

Copies of copies get less precise, and worn keys don't lift the pins cleanly.

Before you startDon't force a key that won't turn. A snapped key in the lock turns an easy fix into a locksmith call.

Let's fix it

0 of 5 done
  1. Test with the door openTurn the bolt with the door open. Smooth means alignment; stiff means lubrication.
    Deadbolt turned with the door open to see whether it moves smoothly or sticks
  2. Lubricate a stiff lockPuff dry graphite into the keyway, then work the key and turn the bolt 10 times. Skip oil or WD-40, which attract dust and gum up locks.
    Dry graphite puffed into the keyway of a deadbolt, then the key worked in and out
  3. Find where the bolt hitsRub lipstick or marker on the end of the bolt, close the door, and turn it. The mark on the strike plate shows exactly where it's catching.
    Lipstick rubbed on the end of a deadbolt leaves a mark on the strike plate showing where it catches
  4. Tighten the hinges firstA bolt hitting low often means the door sags. Tighten the hinge screws, and swap one top-hinge screw for a 3 inch screw into the stud.
    Top door hinge with a 3 inch screw going in to lift a sagging door back into line
  5. Adjust the strike plateIf it's still off by a little, file the opening in the strike plate slightly toward the mark. If it's off by more, move the plate.
    Small file widening the strike plate opening slightly toward the lipstick mark

Still not fixed?

If it still sticks after graphite and alignment, the lock mechanism may be worn. Replacing a deadbolt is a straightforward DIY job with a screwdriver.

Seasonal sticking on an exterior door usually means the door shifts with humidity. Adjusting the strike plate slightly usually covers both seasons.

Tip from experienceIf the key itself is worn smooth, have a new copy made from the original key, not a copy of a copy. Worn keys cause many "sticking locks."
Time to call a pro if you seeA lock that won't turn at all, a key broken off inside, or a door that won't secure. Security problems deserve a same-day fix.

What a pro charges: A locksmith typically charges $75–$200 for a lock repair or rekey.

Common questions

Can I use WD-40 on a lock?

It's better to use dry graphite or a lock-specific lubricant. Oil-based sprays attract dirt and can gum up the pins.

Why does my deadbolt only stick when the door is closed?

The bolt and the strike plate hole don't line up, usually because the door sags. Tighten the hinges or adjust the strike plate.

About the authors

Grab the Hammer Team

We're a small team of home repair writers and editors who test our advice against manufacturer instructions and common code requirements. Our goal is simple: help you fix what you safely can, and know when to call in a pro.

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