Quickpost: Fixing A Duplicate Key

I had a locksmith make a duplicate key of my mailbox lock, and it didn’t work (didn’t open the lock).

The cutting looked good, I saw no difference with the original key.

Until I noticed this notch:

Turns out this notch accepts this tiny “bump” on the cylinder:

This notch was missing on the duplicate. I milled a notch and now the duplicate key opens the lock:

Quickpost info