Is there a quick and simple way to know if you are looking at a key or lock from an A2, A3, or A4 SFIC system?
All I (think I) know about them (based on a couple of PDFs I found online) is:
Difference between pin lengths:
A2: 0.0125"
A3: 0.018"
A4: 0.021"
Number of possible key bitting depths (based on this key reader:
http://www.lab-lockpins.com/images/lkgic.jpg)
A2: 9
A3: 6
A4: 5
Total pin stack height (though I have read that this is only a suggestion)
A2: 23
A3: 16
A4: 14
So the ways I see how to possibly figure out which system is in use are:
-Disassemble a core and measure pins, but this is no guarantee as you may not have every possible pin length. I guess you can look for multiples of the difference (since .0125, .018, and .021 don't have a common divisor) but I don't know how much mechanical wear would factor into this.
-Similarly, 'decode' a key (using a tool similar to the above, or by measuring the bitting cuts) but again you may not have every key depth present.
-Disassemble a core and measure overall pin stack and hope it equals 23, 16, or 14, but this is not guaranteed; the locks will work with different stack heights and whoever combinated them may ignore the guidance given by the manufacturer
All of these are more likely to help if you have access to more than one key and/or lock.
Is there any simple way to know (or get a good hint) as to which system is in use on any given lock?
