Pin Tumbler Lock Physics

Demo + Build Your Own Key
SHEAR LINE Drag the key. Aim to align the pin gaps to the shear line.

Make a Key

Set each tooth depth (0 = shallow, 9 = deep). Helper snap reduces frustration by snapping when you are close to the correct depth.
Close hides this panel only (you are still in Make Key mode).
Drag the key in. Align the pin gaps to the shear line.
Demo: Correct