A key snaps when a worn blade meets a worn cylinder. Consequently it almost never happens without warning. The break is the visible event, but the wear behind it has usually been building for months.
Why winter is worse
Brass turns brittle below freezing. Meanwhile grease inside the cylinder thickens and drags. Consequently the same force that worked in September shears the blade in January. Therefore Ottawa locksmiths see a clear spike in broken keys between December and March, and it is not coincidence.
How the fragment comes out
Thin hooked or spiral extractors slide alongside the blade, catch the cuts, and draw it out. Success depends on how deep the break sits and whether the pins are resting on top. Consequently turning the plug back to vertical first often makes the difference between two minutes and forty.
What makes it harder
Superglue on a matchstick is the classic mistake, because it bonds the fragment to the pins. Similarly, pliers push it deeper when there is nothing to grip. Furthermore, blind drilling destroys the cylinder. Therefore the most useful thing you can do after a break is stop.
If a little is showing
Fine tweezers pulling straight out sometimes work. However, do not twist, because twisting wedges it.
You will need a new key
Both halves are scrap. For a house key we cut a replacement on site, either from the fragments or decoded from the lock itself. For a car key it depends on the type, since transponders and proximity fobs need programming as well as cutting. Consequently it is worth cutting two while the van is there.
Questions we get about this
Can the lock be saved?
Usually yes. Extraction removes the fragment and the cylinder keeps working.
I tried pliers. Is it ruined?
Probably not. Failed attempts make it harder rather than impossible.
Why did it break?
Worn key, worn cylinder, or both. Moreover cold weather accelerates it.
Can you cut a new key without the original?
Yes, decoded directly from the lock.
Should I replace the lock too?
If it was already stiff, yes. Otherwise cleaning and rekeying is enough.
