Master key systems without master pins

all keyed the same.... --Shiva--

what makes ya think they were master-keyed ?

Did you see a tiny hole alongside each pin chamber on the plug? If yes, they use 3 tiny ball bearings in place of a master pin. If not, they were just KA, not MK

IF this lock was indeed part of a master keying system its' bitting was a keyed alike group and the lock you took apart was (NMK) "Not Master Keyed". Are you sure that this is the case ? A group of locks all opened by one key can also be (KA) keyed alike as others here have mentioned...

I don't know which paper you have read, but in Blaze's writing: "Rights Amplification in Master-Keyed Mechanical Locks" he mentions the two most common schemes for creating a master key system. (RC) 'Rotating Constant' in which all change keys share one or more cuts with the TMK and (TPP) 'Total Position Progression' in which change keys do not share any cuts with the TMK...

You are perhaps thinking of rotating disc type locks such as Abloy that can accomodate master keying by using discs that allow more than one key bitting depth in a particular bitting location to operate the lock by having more than one gate cut into the disc...

I think it based on what you have described that your lock is either not master keyed at all, rather it is one lock in a KA group, or if it is a part of a master keyed system it is the condition I described above...

Evan, ~~ formerly a maintenance man, now a college student...

Possibly the first 'modern' masterkeying was with Bramah locks 200 or so years ago. A masterkeyed Bramah lock had provision for 8 sliders but only 6 were used somewhat like the rotating costant mthod. This gave 28 differs under a masterkey would would have sufficed for a manor house or suchlike (as these locks would have been used at critical points only) and there would have been no loss of security compared with a regular 6 slider model since the sliders still had one only slot.

The ancient Egyptian pin tumber lock could have been masterkeyed the same way with 8 holes but only 6 pins. Change keys would have had 6 pegs, the masterkey 8. Would be interesting to know if ancient locksmiths actually did this. Doubt it.

AFAIK Kaba cylinders use the same principle with provision for 22 or so pins but not all positions are used (I stand corrected if need be).

Is there a chance that this lock came from a door that should only be opened by persons issued the Grand Master Key, and thus was pinned to this key only?

An example might be a security office door.

Could it also simply be keyed-alike and whilst in the same building and keyway, not be on the master-key system. I know some places have plant-rooms etc keyed like this, as you are either maintenance staff permitted in all plant rooms, or not, and the risk of a padlock to say the gas meter cabinet being smashed off then decoded for the grand master key bitting is too high a risk compared with security having two keys to carry around (if they must have the ability to enter a plant room without returning to the office at all)

Locks can be masterkeyed to a degree based on their keyway where one key will fit several keyways on the system but other keys will only fit one of the several distinct keyway wardings but with your kwikset AFAIK that isn't going to be the case. The odds are your lock just isn't part of a masterkey system even if it's used in a building where some locks are masterkeyed, or it's simply keyed alike to other locks as would be common practice with janitors closets and things of that nature.