Do MACS change when using different pins?

[Krullie]

Recently I heard about MACS (Maximum Adjacent Cut Specification). I was wondering if these change when using a different type of pins as I assume a key would have more trouble to correctly align when using high security pins (for instance mushroom or T-pins).

Any good resources where I can find manufacturers MACS? For instance Abus (Model 72 and 83)?

[cledry]

No, MACs is about the key not the lock. If you exceed MACs you are removing material from the key in the shallow cuts.

[l0ckcr4ck3r]

MACS is about the cuts made on the key as cledry has already mentioned but it is set to allow for smooth operation of the lock and prevent the key getting jammed in there.

Changing the Driver pins will have no effect on this but swapping out the key pins from flat to conical ones may actually cause some problems.

[cledry]

It isn't really set to provide smooth operation, that is based more on stack height and springs. Its purpose is to prevent removing part of a cut on the key.

[Jacob Morgan]

Recently I heard about MACS (Maximum Adjacent Cut Specification).

If you are interested in what MACS is all about, there is a very detailed explanation of it (along with the math behind it), in Graham Pulford's book High-Security Mechanical Locks. The book is expensive but worth it, I've enjoyed my copy.

[RumballSolutions]

+1 for Graham's book, any one with an interest in locks should own it.

[GWiens2001]

Agreed about Graham Pulford's book. It explains many things about locks and lock mechanisms. It belongs in every lock lover's library.

You can also learn a lot about locks and picking them from Practical Lock Picking, by Deviant Ollam.

Gordon

[Krullie]

thanks for the replies, so as long as the keypins are not altered it should have no impact on how smooth the key can be inserted and retracted.

As a side note: I own and have read Deviant Ollam's book. Love his video's too, he's a great public speaker.

Will check out the other book too, but found the formula on lockwiki:
http://www.lockwiki.com/index.php/MACS

[LocksportSouth]

It's a shame that MACS is a thing. Min-Max-Min-Max cut keys would make for a hell of a picking challenge, and if you packed the lock with security pins, too...

I guess as long as the slopes of the key aren't too steep, you could violate macs? As in, the lock should still work if the pins can still travel up the slopes - it would just make the key tougher to insert and remove, and weaken the key structure a bit, right?

[GWiens2001]

The problem is not just the ramps (slopes as you called them). The problem is spacing between pins combined with the difference in heights between the bittings combined with the ramps. Eventually, you can not avoid having slope angle correct and still have there being a bitting at the next height.

Gordon

[kwoswalt99-]

Violating MACS can also lead to excessive wear on the springs.

[cledry]

You want to play with wicked MACs try cutting and pinning using a Sargent cutter and pins. You will get some really wild looking keys. Now stick a few security pins and different spring rates combined with Sargent's tight tolerances and it should make a nice challenge.