The Difference Between Lock Lubricants (and What NOT to Use)

Most lock problems don’t start with break-ins or broken keys. They start quietly—your key feels a little stiff, the lock needs a jiggle, or it works fine one day and resists you the next. That’s usually when homeowners reach for the nearest can under the sink or in the garage.

And that’s where things go wrong.

At Brothers Locksmith, one of the most common phrases we hear is:
“I sprayed something in it, and now it’s worse.”

Lock lubrication matters far more than people realize. Using the wrong product doesn’t just fail to help—it can slowly destroy the lock from the inside. Let’s clear up the confusion and explain what actually works, what doesn’t, and why locksmiths are so picky about this topic.

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Why Locks Need Lubrication in the First Place

A door lock may look simple, but inside it’s a tight system of pins, springs, chambers, and moving metal parts. Over time, dust, humidity, temperature changes, and everyday use cause friction inside the cylinder.

When lubrication is done correctly, it:

• reduces internal friction
• prevents metal wear
• keeps pins moving freely
• protects against moisture buildup
• extends the life of the lock

When it’s done incorrectly, it attracts dirt, gums up pins, and turns a smooth lock into a sticky mess.

Dry Lubricants: What Locksmiths Actually Prefer

If you asked ten professional locksmiths what they trust most, the answer would almost always be a dry lubricant, especially graphite or PTFE-based products.

Dry lubricants work because they don’t stay wet. That’s critical.

Inside a lock, wet substances attract dust, grit, and debris. Dry lubricants coat the internal components lightly and allow pins to glide without turning the cylinder into a dirt magnet.

Graphite powder, when used sparingly, has been a locksmith staple for decades. Modern PTFE (Teflon-style) dry sprays offer similar benefits with less mess and better performance in humid or coastal environments.

Brothers Locksmith often uses dry lubricants during routine maintenance because they keep locks smooth without creating long-term buildup.

Why Liquid Lubricants Feel Good at First—Then Ruin the Lock

Here’s the trap homeowners fall into:
They spray a liquid lubricant, the lock instantly feels smoother, and they assume the problem is solved.

But inside the lock, something else is happening.

Liquid lubricants—especially oil-based ones—coat the pins and springs. Dust sticks to the oil. The oil thickens over time. Eventually, the pins start sticking instead of sliding.

What felt like a fix becomes a slow failure.

This is why many locks that “suddenly stop working” actually fail months after the wrong lubricant was used.

WD-40: The Most Misused Product in Lock History

Let’s clear this up once and for all.

WD-40 is not a lock lubricant.

It’s a water displacement spray designed to loosen rust and displace moisture temporarily. While it can free a stuck lock in an emergency, it leaves behind a residue that attracts grime and dries into a sticky film.

At Brothers Locksmith, WD-40 is often the reason we’re called to replace a lock that could have been saved.

If WD-40 has already been used, a professional cleaning is usually required to flush out the residue before proper lubrication can be applied.

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Grease and Oil: A Guaranteed Way to Kill a Lock

Household oil, motor oil, cooking oil, grease, or any thick lubricant should never go inside a lock.

These substances:

• trap dust aggressively
• thicken over time
• slow down pin movement
• cause internal sticking
• lead to key breakage

Once grease is inside a cylinder, there’s no easy DIY fix. The lock often needs to be disassembled or replaced entirely.

This is one of the most expensive “small mistakes” homeowners make.

Spray Silicone: A Gray Area That Depends on the Lock

Silicone spray sits in a tricky middle ground. It’s not as harmful as grease, but it’s not ideal for pin-tumbler cylinders either.

In some cases—like door hinges or sliding mechanisms—silicone is excellent. But inside traditional locks, it can still leave residue and interfere with pin precision over time.

Some modern smart locks and latch mechanisms may tolerate silicone in specific areas, but locksmiths are very selective about where it’s used.

What Happens When the Wrong Lubricant Is Used Long-Term

Locks damaged by improper lubrication often show the same symptoms:

• keys getting stuck halfway
• locks working only after “wiggling”
• difficulty turning during cold or hot weather
• keys snapping inside the cylinder
• complete lock seizure without warning

By the time these symptoms appear, the internal damage is often advanced.

That’s why Brothers Locksmith emphasizes prevention, not emergency fixes.

How to Lubricate a Lock the Right Way

Proper lubrication is less about quantity and more about precision.

A small amount of dry lubricant applied directly into the keyway is enough. The key is then inserted and turned several times to distribute it evenly.

Over-lubrication—even with the right product—can cause issues. More is not better.

And if a lock hasn’t been serviced in years or already feels gritty, professional cleaning before lubrication may be necessary.

Smart Locks Still Need the Right Lubrication

Many homeowners assume smart locks don’t need maintenance because they’re electronic. That’s a mistake.

Smart locks still rely on:

• mechanical bolts
• internal gears
• key override cylinders

Using the wrong lubricant can strain motors, cause false “jam” errors, and shorten the life of the electronics.

Brothers Locksmith often sees smart lock failures caused not by software—but by mechanical friction from poor lubrication choices.

When Lubrication Isn’t the Real Problem

It’s important to say this clearly: not every stiff lock needs lubricant.

Sometimes the issue is:

• door misalignment
• frame shifting
• worn keys
• internal mechanical damage
• poor installation

Adding lubricant in these cases may mask the problem temporarily but won’t fix it. A locksmith inspection can prevent unnecessary damage and replacement.

Conclusion: The Right Lubricant Saves Locks—The Wrong One Destroys Them

Lock lubrication seems simple, but it’s one of the most misunderstood parts of home maintenance. The wrong product can silently ruin a lock that would have otherwise lasted years.

If there’s one takeaway, it’s this:
Dry lubricants protect locks. Oils and greases destroy them.

And if you’re unsure what’s already inside your lock, it’s safer to call a professional than to guess.

Brothers Locksmith helps homeowners fix lubrication damage every week—but the best calls are the ones where the lock is saved before it fails.