How to Lubricate a Door Lock | The Right Way to Do It

When a lock starts sticking, the instinct is to grab whatever oil is handy and give the keyhole a good dose. That’s the exact mistake that turns a minor annoyance into a full replacement job. Oil and grease attract dust and grit, which builds up inside the mechanism until the lock seizes completely. The fix for a sticky door lock is a dry lubricant, applied in small amounts, and the whole job takes about two minutes. Here’s how to do it without making things worse.

What Lubricant Should You Use On A Door Lock?

Stick with a dry lubricant made for locks—either a PTFE/Teflon spray or powdered graphite. These dry into a film that reduces friction without leaving a sticky residue behind. Master Lock’s technical manual recommends its own Lock Lubricant for its padlocks, applied as a very light spray to the keyway and shackle holes. ASSA ABLOY, one of the world’s largest lock manufacturers, offers the same guidance for its cylinders.

That means your options are:

• PTFE/Teflon spray — the most versatile choice, works on most lock types and doesn’t attract dust
• Graphite powder — a classic dry option, though messier to apply and not recommended by ASSA ABLOY for its own cylinders

ASSA ABLOY is blunt about what not to use: “Never use grease, oil or graphite-based lubricants in locking cylinders.” The company warns these can disrupt function and clog the mechanism. Oil might make the lock feel smooth for a week, but the residue collects dirt and eventually turns into a paste that jams the pins. If you’re looking for a product recommendation, our tested door lock lubricant roundup covers the top picks for different lock types.

How To Apply The Lubricant (Step By Step)

The process is short, but the details matter. Here’s the sequence that works for padlocks, deadbolts, and most cylinders.

1. Clean the keyway first. If you can see visible dirt or debris near the keyhole, blow it out with canned air or wipe it away with a dry cloth before you spray. Lubricant over grit just makes the grit stick.
2. Insert the spray nozzle into the keyway. ASSA ABLOY’s guidance says to press for about one second—a short burst, not a flood. Master Lock echoes this with “very light spray.”
3. Work the key in and out. Insert the key and turn it back and forth several times to distribute the lubricant through the pins. A couple of turns is enough.
4. Wipe off excess. Run the key with a clean cloth and wipe the exterior surfaces around the keyhole. Leftover lubricant on the surface just collects dust.

For padlocks, give the shackle holes a quick spray as well, then cycle the open/close action a few times so the lubricant reaches the locking mechanism inside. You’ll know it worked when the key turns smoothly and the lock operates without catching.

How Often Should You Lubricate A Door Lock?

Most locks don’t need constant attention. ASSA ABLOY recommends servicing cylinders twice a year, or according to your building’s maintenance schedule. Other guidance suggests every three months for exterior locks exposed to weather, which works out to about 2–4 times per year depending on your climate.

If the lock is in a sheltered spot and turns smoothly, leave it alone. Over-lubricating is the more common mistake than under-lubricating—excess lubricant attracts dirt and leaves residue inside the mechanism. A small amount applied twice a year beats a heavy dose every month.

One note on mixing: don’t layer a new lubricant over an old one of a different type. If the lock has previously been oiled and gummed up, clean the keyway as best you can before switching to a dry lubricant, or the two products can react and make things worse.

Common Mistakes That Ruin Locks

The biggest errors are all variations on using too much or using the wrong product. Here’s what to avoid, and what to do instead.

• Don’t use oil or grease in cylinders. ASSA ABLOY explicitly prohibits it—these products clog the mechanism over time.
• Don’t over-apply. A one-second spray is plenty. Flooding the keyway leaves residue that becomes a dust magnet.
• Don’t skip the cleaning step. Applying lubricant over grit pushes the debris deeper into the pins.
• Don’t mix lubricant types. Choose one product and stick with it; switching between graphite and PTFE can leave a pasty residue.
• Don’t lubricate a lock that’s already seized. If the key won’t turn at all after cleaning, the problem may be broken pins or a misaligned strike plate, not friction. Those need a locksmith, not more lubricant.