Broken Key Extraction: what the visit covers

A car key that breaks in the door or the ignition is handled with the same extraction tools, with one difference. On most vehicles the plastic head of the key carries the transponder chip and the remote buttons, and that half is usually intact in your hand. Once the blade is drawn out of the lock, a new blade can often be cut and fitted to the existing head, so the chip keeps talking to the car without reprogramming. The ignition wafers are checked for disturbance and the steering lock is confirmed free. Proof of ownership is asked for before work begins.

Reading the cylinder for the cause

Even a lock in good order can break a key that was already worn, bent or fatigued, so the cylinder is examined for a contributing cause all the same. The locksmith looks for grit and salt crust in the keyway, a cylinder cap that has loosened and let the plug shift, pins that have worn flat so the key needs force to lift them, springs that have weakened, and burrs at the mouth of the keyway that drag on the blade. On an exterior door the strike and hinges are checked as well, since a bolt that binds in its pocket makes the key carry the load. Each finding shapes the advice given once the fragment is out.

The spiral extractor for a stubborn piece

When a fragment sits flat in the keyway with its cuts facing the pins and nothing for a hook to catch, a spiral extractor is the tool. It looks like a very fine screw on a handle. Slid alongside the blade and turned gently, its threads bite into the ridges of the key cuts and grip them. The locksmith then pulls straight back, and the fragment comes with it. A second spiral from the other side of the blade is sometimes used to steady the piece. It is slow and careful work, and it leaves the pins and springs exactly where they were.

A cylinder that has been looked after

Extraction usually doubles as a service. The keyway has been blown clear of grit and salt, the pins and springs checked for wear, the cylinder cap snugged if it had loosened, and dressed with the lubricant its maker specifies rather than a one-size-fits-all product, since some cylinders take a dry graphite or PTFE spray and others forbid graphite outright. General household oils and sprays commonly collect dust and clog the pin chambers. A puff of the right lubricant twice a year, spring and fall, keeps the cylinder turning freely, and a key that starts to need force is an early message worth acting on before it breaks.