Broken Key Extraction: what the visit covers

Two facts shape the job before the locksmith arrives: whether the door is locked or unlocked, and whether any of the key is showing. A fragment that protrudes can often be gripped and drawn straight out. One flush or deep needs extractors worked in alongside it. If the plug turned before the key broke, it has to be eased back to its resting position first so the pins line up and release the blade. A locked door means the extraction is followed by opening the lock; an unlocked one means securing it is the priority. Either way the door ends up locking with a key that fits.

How the piece is sitting

The first look is at the fragment itself, without touching it. Does any of the blade show above the cylinder face, or is it flush or deeper still? Is the plug sitting at its normal rest position, or did it stop partway round when the key gave way? A protruding piece in a resting plug is the simplest case. A fragment past the shear line in a rotated plug means the pins are holding it, and the plug has to be brought back before anything will slide. Reading this correctly decides which extractor comes out of the case and spares the keyway from needless probing.

Bringing the plug back to rest

Nothing slides out of a rotated plug, because the pins that the key lifted are still sitting at the shear line and holding the blade. So when the key snapped mid-turn, the first job is to return the plug to its resting position. The locksmith applies gentle rotational pressure with a tension tool, feeling for the point where the pins drop back into the plug and the keyway lines up with the cylinder body. Sometimes a light tap on the face helps the pins settle. Only once the plug is at rest is the fragment free to move, and only then do the extractors go in.

A door that no longer fights the key

If the bolt had been dragging in its strike, that is corrected while the locksmith is there, because a bolt that binds turns every key into a lever. Dropped hinges get longer screws driven into the framing; a strike pocket that pinches the bolt is filed or shifted; a weatherstrip that was pushing the door off square is pared back. The test is simple: the thumb-turn should throw the bolt with one finger and no push on the door. Since wood swells in humid summers and shrinks in dry winter air, a seasonal glance at the screws keeps the key from taking the strain again.