Broken Key Extraction in Cambridge, MA

Where keys break in Cambridge

A key usually snaps where it takes the most twisting, and in dense housing that is often a shared lock. The city's neighborhood planning puts about 7,000 residents in The Port, a high-density neighborhood. In a building split into apartments, one street-door cylinder may serve several households, and a worn cylinder makes a key stick. A stuck key gets forced, and a forced key breaks.

Common trouble spots:

• Building street doors, where one cylinder takes every resident's key.
• Mailbox locks, whose small, thin keys bend easily.
• Older cylinders. Roughly three in ten Massachusetts homes predate 1940, according to the Census Bureau's 2024 survey, and a cylinder with worn pins binds more easily.

A key that snapped in a shared street door affects more than one household, because the door may be the only way in for everyone in the building. Tell the owner or manager as soon as it happens.

What not to do

• Do not try another key in the same lock; it can push the broken piece deeper.
• Do not put glue into the keyway; it can seal the cylinder shut.
• Do not spray oil in; it collects grit and leaves residue on the pins.
• Do not keep turning the stub if the fragment is flush; you can jam the cylinder.

Keep the half you are still holding. The two pieces together can often be used to cut a replacement key.

What to send

Say which lock it is (street door, unit door, mailbox or rear porch door), whether the door is locked or unlocked, and whether any of the fragment sticks out past the face of the lock. A close photo of the keyway helps. Details are on the broken key extraction page, and a cylinder damaged along the way may need lock repair. The Cambridge page describes the neighborhoods in more detail.