A cylinder holding damaged or deteriorated parts can still take the key just fine while refusing to let the mechanism move normally. Since that internal

A lock can develop trouble on the inside well before it shows up at the keyway, which is why restricted rotation is often the first

Grime and debris built up inside a lock can keep the internal mechanism from responding the way it should, even when the key itself is

Precise contact between a key and its cylinder is what makes rotation possible, and once that contact degrades, turning gets harder fast. Keep forcing it

Internal damage is the usual explanation when a key slides into the cylinder easily but won’t turn, since something inside is restricting movement rather than

Rotation can stop short even though the key seats fully, a sign that something inside the cylinder has shifted out of alignment. Pushing harder rarely

Cylinder problems can affect rotation separately from insertion, letting a key go all the way in while the mechanism itself stays stationary. Bending or twisting

A professional locksmith can assess the mechanical condition of a lock to work out why it’s no longer responding the way it should, examining internal

Force a key through persistent resistance long enough, and it can ultimately snap, leaving a broken piece lodged inside the lock. Built-up debris is a