What kind of lock is this?!

[vandelay]

I always see these hey holes being used on doors that are for these funny keys that kind of just look like 2 normal pin tumbler keys stuck together with a small gap between them. when you look at the keyhole it sort of resembles a square without the top part. Kind of like a "U" that is flat at the bottom with the 2 edges squared off. I have no idea what theyre called and i cant find a picture but theyre pretty common here in Australia. I remember seeing them on staff doors in high school and i still see them at the uni library. Does any one know what these are called or how they work? and how come ive never seen this key and lock used on a padlock? do they sell them? Ive never even seen them being mentioned in any lock picking forums either although theyre not that uncommon.

[MacGyver101]

They're made by a company called Australian Lock Company; that design of locks is called BiLock. There's a fair amount of information about them here if you search around: they're well-regarded as a very secure design.

[Squelchtone]

... how come ive never seen this key and lock used on a padlock? do they sell them? Ive never even seen them being mentioned in any lock picking forums either although theyre not that uncommon.

Click the link for aBilock Padlock Brochure

Not suer what forums you were looking at but people here talk about them all the time. I wish I had one so I could join in on the conversation.

Squelchtone

ps. There are some shops online that sell Bilock cores inside other brand padlocks such as Abus, a well known German padlock company. Check some out here