security pins...what are they?

[mcs66]

I'm new to the forums, and have seen people discussing "security pins" often on the site, but haven't found a good explanation as to what they are and how they are different from normal non-security pins. I remember seeing on one thread that the MasterLock 140 padlock had security pins, and that is the lock I have been practicing on and have been able to open pretty reliably. Does this mean that other locks will actually be easier? Thanks in advance.

[Jaakko]

This shows how the security pins "jam" the rotation of the plug, giving a false set: http://www.sanitarium.net/golug/physical_security-pics/pin_types.jpg

Here is some examples:
Mushroom pin
Serrated pin
Spool pin

Also there are variations of these basic types, fo example "spoorated", which is like a spool but with also small serrations at the ends.