Question on pin order for SPP

[ckc123]

one thing I have noticed on a lock (and wanted to confirm with people who know..)

I've noticed that with one lock I have, that if I use the reverse side of a pick and hold all the pins "up".. if I apply a lot of pressure on the tension wrench, all the pins are stuck up.. if I then remove the pick, and let up ever so slightly on the wrench, I can get the pins to release one be one.. (Say in pin order 4-3-1-2). when I SPP the lock it's the opposite order that I use to open the lock.. (2-1-3-4)

is this the same with most other locks??

[EmCee]

When you SPP you apply gentle pressure on the wrench to find the first binding pin then the next and the next. When lifting all the pins, the torsion obviously has to be enough to bind that last binding pin and by definition must therefore be more than enough to bind the previous pins. When you ease pressure on the wrench, the pins fall back one by one as the pressure on each is reduced to the point where the binding force ceases to hold it up. As a result the pins drop in 'reverse' order - although it might not always happen exactly that way with every lock.

In fact, this 'reverse' approach can sometimes be a useful technique. If you deliberately overset all the pins above the shear line and then carefully 'feather' the wrench to ease pressure bit by bit, you may drop all pins to the shear line and open the lock.

Cheers...

[LocksmithArmy]

in short yes... the same reason you have a binding order is the reason some pins fall first. the minute differences making one pin bind last wil inherently fall first when you apply tension like this... and while i have never thought abt it it seems like a viable way to figure out the binding order b4 you even pick... as long as you can stop and apply your tension between each pin drop to see which one fell...

and as mentioned before it CAN pick a lock. its called reverse picking... its simply raising all the pins and slowly releasing tension... if only keypins drop... the lock will open...

nice work btw.

[LocksmithArmy]

I should also add (before I am shunned) that it does not always yield the inverse binding order... because your otigional binding order if off the driver pins and your inverse one is off the keypins...

[luckey]

Interesting question though. I liked that as it got me really thinking about what goes inside a lock.