What is the term for the boundary where key pins and driver pins must align for the plug to rotate?

Answer

Shear line

When all the key pins are lifted to the exact right height, creating a straight line across the boundary between the key pins and the driver pins, this boundary is known as the shear line, allowing the plug to rotate freely.

What is the term for the boundary where key pins and driver pins must align for the plug to rotate?
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