How a Pin Tumbler Lock Works | 3D Cutaway Built to Real Schlage Specs

Five tiny pins decide whether your door opens. We built a real Schlage lock in 3D, to its factory measurements, and cut it in half so you can watch every pin move. In this video: • What the housing, plug and keyway do • Why the shear line is the whole secret • Why one cut, wrong by just 0.38 mm, keeps the lock shut • How a five-digit key code works, and why only 79,666 of 100,000 codes are usable • How master keys work • Where the pin lock came from Built to real specs: Schlage SC1 key (bitting 4-7-2-6-3), cuts .231" from the shoulder then every .156", depths .335" to .200" in .015" steps, a 12.7 mm plug and 2.92 mm pins. Every pin's motion is calculated from the key surface under it. Chapters 0:00 Five tiny pins 0:22 Housing, plug and keyway 0:47 Inside the lock 1:16 The shear line 1:40 How the key lifts the pins 2:01 Why the right key works 2:25 Turning the plug 2:43 One step wrong 3:09 Key codes and combinations 3:46 Master keys 4:08 The history of the pin lock 4:36 Next: the differential Parts & Motion: machines, opened up. New video every Saturday. #HowItWorks #PinTumblerLock #3DAnimation