Kwikset Titan - what are the extra cuts in the plug for?

[ChemicalRobot]

So I recently purchased a Titan deadbolt lock at Goodwill for a couple of dollars (without the key, unfortunately). I promptly took it apart a few minutes ago and I had a question. What are the holes on the plug next to the normal ones for? They are shallow and have a smaller diameter. I'd upload a picture but I don't have a camera available at the moment.

[bezza1]

i think thay are for construction keying where thay put verry small ball bearings as pins so when the job is fnnished the owner puts there key in and the ball bearings fall into the holes so now the builders key no longer works hope this helps

[bezza1]

this is a pic

[ChemicalRobot]

Hah, if that's the case then that's really neat actually.

Do builder keys only have two key pin sizes (no bearing and 1 bearing)? I can't see more than one bearing being able to fit into the builder plug holes for when they fall in.

[bezza1]

no i nont no about the key depths these are some builders keys ive got for a

[the lockpickkid]

Bezza, exactly right. There holes used to trap the balls for construction keying, I actually took apart a lock once and there was some inside it. As far as the holes being too small?? These bearing things are tiny, I have some, I think you could nearly fit 20 of them in one hole, just to give perspective. ChemicalRobot, great question, it has been asked a couple of times, and has even stumped alot of people!!! Keep the questions coming!!

They are called PK Balls, the name escaped me for a bit, here is a link with a refrence and pictures.

http://www.doorlocksdirect.com/82208.html

[magician59]

Hah, if that's the case then that's really neat actually.

Do builder keys only have two key pin sizes (no bearing and 1 bearing)? I can't see more than one bearing being able to fit into the builder plug holes for when they fall in.

When the cylinders are construction master keyed, the master key generally works every lock in the development. the difference between the master key and the end-user's key in the mastered chamber is half an increment in depth. three small ball bearings are loaded into one chamber to give the (usually 5-1/2) depth for that particular cut. When the end user inserts his key, the bearings are driven up into the bible, and then deposited into the mating hole as soon as it passes under the top chamber. It is thusly "dropped out" of play, effectively disabling the master key. A conscientious locksmith will Completely remove any extraneous master pins, when called to rekey such a house, otherwise, other incidental "master" keys will work the locks.