Worn keys can damage “wafer” tumblers or pins inside the lock cylinder so that the key can’t turn, preventing the ignition from unlocking. The wafers themselves can wear down (so much so ...

The deadbolts we’ve tested, both conventional and smart, are usually single-cylinder, operated using a key (or keypad and PIN) from outside or a thumb-turn from inside. The high-security locks ...

When the key is placed in the lock, it not only moves the pins to the correct height, it also rotates them to the correct orientation. A sidebar blocks the cylinder unless the pins are rotated ...