extra holes in door lock

[vinnie]

Hey, first time posting here. I took apart this door lock I had sitting around. Have no idea what company makes it as there's no writing at all on it. On the barrel there is an extra set of holes drilled, but only part of the way through (see picture). Can anyone tell me what these are for? The only thing I could think of was that it's a mistake in manufacturing.

Thanks

[keysman]

No , no mistake.. The extra holes are used for construction keying.. when the home is being built there are many keys that go out, for carpenters painters , plumbers ect .. the contractor can give a key to the sub- contractor... no need to get it back or worry if the key has been copied.
When the home owner takes possession of the house the first time the new key is used it cancels the “ construction key “.. there are little balls that fall into the extra holes.

A complete description here: https://sites.google.com/site/keyingsol ... /downloads

[vinnie]

No , no mistake.. The extra holes are used for construction keying.. when the home is being built there are many keys that go out, for carpenters painters , plumbers ect .. the contractor can give a key to the sub- contractor... no need to get it back or worry if the key has been copied.
When the home owner takes possession of the house the first time the new key is used it cancels the “ construction key “.. there are little balls that fall into the extra holes.

A complete description here: https://sites.google.com/site/keyingsol ... /downloads

oh ok. that makes a lot of sense. especially since this particular lock was one they were chucking out at a construction site I was working at.