SolidPaint wrote:10-15 years ago, I worked for the owners of houses that were being built, the owners and myself had one key that opened all of the buildings and once someone bought the house, they got a different key. Once this key was used, our keys did not work anymore. What is this type of lock called?
That way of pinning up a lock is called Construction Keying. It uses little balls in place of one of the pin chambers, when the second the home owner inserts and turns their key, the little balls fall out, and the contractor's key no longer works because the cuts on his keys no longer match the pins inside the lock.
here's a thread discussing it:
viewtopic.php?f=8&t=55450&start=15
