Locks are mechanical devices with moving parts — and like any mechanical device, they benefit from regular maintenance. A well-maintained lock operates smoothly for decades. A neglected one seizes, fails, or becomes a security liability. Here's how to keep yours in top condition.
A stiff or scratchy lock almost always needs lubrication. Use a dry lubricant — graphite powder (from a squeeze tube) or a Teflon/PTFE spray like Tri-Flow. Spray or insert graphite into the keyway, insert and remove the key several times to distribute it. Never use WD-40 — it's a solvent, not a lubricant, and attracts dirt over time.
Debris, dust, and old lubricant accumulate in the keyway and affect key insertion. Use a can of compressed air to blow out loose debris. For stubborn buildup, a locksmith can disassemble and ultrasonically clean cylinders. Perform this annually for exterior locks.
Wiggle every door lock. Loose mounting screws allow the lock to shift under load, wearing out faster and potentially allowing manipulation. Tighten all visible screws. Loose deadbolts or knobs often just need a few turns of a screwdriver.
A misaligned door causes the bolt or latch to drag against the strike plate, creating wear on both. If the door has sagged, you'll see wear marks on the strike plate or feel resistance when locking. Adjust the hinges or strike plate to restore alignment.
Replace locks that are: over 15 years old, visibly corroded or damaged, require excessive force to operate after lubrication, or have been in a break-in attempt. Also replace if you've lost track of all keys issued.