On Fri, 30 Nov 2018, Jon Elson via cctalk wrote:
Those are the 8 possible DEPTHS of the grooves cut
into the key.
So, that gives a possible combinations of 8 to the 7th power, I think.
These depths correspond (with an offset) to the lengths of the tumblers
(pins) in the lock.
So, if you know what the length of a tumbler is, you can add the offset and
figure out what depth groove to cut in the key.
No, they are the depths of the grooves cut into the key.
The low numbers are a shallow cut.
Sometimes, people mistake the #1 cut for not being cut.
Although the combinations are 8^7, often a cut that is one off will still
work, so there are fewer usable combinations.
And in a conventional lock (non-tubular), it is a BAD idea to have the
deepest cut right near the bow (handle), or the key will break/wear out
prematurely. And some lock companies advise against having an extreme
difference between adjacent cuts. 1,9,1,9,1 will be hard to get in and out
of the lock. And, some lock companies pick patterns of only having even
number cuts for some positions and only odd numbers for some others.