Re: Construction Keying

What many don't realize is that all Construction keyed locks are master
keyed. Given a five pin cylinder, if they weren't master keyed then a
given construction MK could at most operate 10 KD locks. The typical
set from lumber yards has a capability for around 200-250. The use of
the owners key will typically remove one or two sets of balls, but the
other three or four chambers remain MK'd. That means there is a MK that
will operate, it just typically isn't ever made and sold to the
contractor.
BBE.
Putyourspamhere wrote:
>
> If these residential locks are truely masterkeyed and you find this
> consistently true in specific neighborhoods or from specific builders send out
> flyers to every house in said neighborhood or built by said builder indicating
> that you have good reason to believe the homeowners lock is masterkeyed and can
> be opened by keys in the possesion of others besides the owners. Offer to check
> the locks for free (if you send the flyer you should already be virtually
> positive the problem exists) then re-key at your regular cost, or sell them
> better locks altogether. You could make a killing and solve a real security
> problem for lots of people all at the same time.

there is a real fast way as well... a 'robbery' with no evidence of break in, OR someone getting attacked and hurt... the lawsuit would kill the builder out immediately and possible the lumber yard as well, especially if someone gets hurt... the liability in that case just might not cover
--Shiva-- nuk pu nuk

It sounded as though the poster was talking about locks that were strictly masterkeyed with no construction keying at all. Therefore the use of the homeowners key would have no effect on the ability of a previously distributed contractors key, in this case a master, to work the lock. Maybe I misread and he meant a lock with both construction and master keying.

Well sure. But why wait for that to happen? If you know the problem exists then fix it for anyone who wants it fixed, and make plenty of $ for yourself at the same time.

that would be a SERIOUS overkill, and in the KW line, sure wear out the lock pretty quick as well as IMO, severely limit the available keys.
--Shiva-- nuk pu nuk

From reading previous postings, it seems that construction and masterkeying together seems to be the norm for tract housing, so builders, subcontractors, inspectors etc have easy access to houses under construction but are 'locked out' when the owner's change key is first used.. As Billy said, a masterkey can be made that cannot be disabled, and one thread a while ago indicated that some builders had such a masterkey to give access for remedial work.
Differs are of course severely limited, but being very cynical 250 is probably sufficient to avoid problems in most situations.
This sort of thing (along with masterkeys for office furniture) does nothing to dispel the 'urban myth' that masterkeys exist that will open all locks.

So have a look at the EVVA 3KS at - what is the security flaw for home users when using this system masterkeyed? I do so, to have my bicycle, my storage and other applications accessible with one masterkey and still being able to give my bike to a friend together with a change key without allowing access to my private rooms. And I feel absolutely secure with this setup!
This is the point - never do this with simple pin tumblers, use some better design for masterkeying.
Even without masterkeying those locks are not worth half the $ they cost.
regards - Ralph

Nothing wrong at all! The problem is with a builder using masterkeyed locks on all the houses he builds so he and his workmen can get into them with only one key. Even if this masterkey is disabled by the new house owner using his own key, it is still possible to make a masterkey (which is slightly different from the builder's one) to fit all these houses.

My point is that there are always master pins in Construction MK'd locks as well as the positions that have the balls that can be removed. I find that it is very easy to loose the balls when following the plug out of the shell and would suspect they were lost and not noticed. I suggest that the lock only had master pins in 3 or 4 chambers and the balls had been removed from the rest.
I have in fact written Construction MK systems for use in institutions and for use in sets sold for residential construction. Those master pins have to be in there unless you only have 5 or 10 different combinations total. You are correct that the home owners should be made aware of this and it would be a good source of income doing all the rekeying to eliminate the problem.
By looking at a few of the different sets it would be a simple matter to make the MK that was never issued and have that key to demonstrate and help make the sale. Manufacturers do take care in designing the systems and there would always be one 'solid' pin in every lock, but not always the same solid pin. That means that every change key would have on it at least one master cut. Nothing more than a simple 2 level Rotating Constant system. BBE.
Putyourspamhere wrote: > > >Subject: Re: Construction Keying > >From: "Billy B. Edwards Jr." snipped-for-privacy@thelockman.com > >Date: 6/23/2003 8:16 PM Eastern Daylight Time > >Message-id: snipped-for-privacy@thelockman.com > > > >What many don't realize is that all Construction keyed locks are master > >keyed. Given a five pin cylinder, if they weren't master keyed then a > >given construction MK could at most operate 10 KD locks. The typical > >set from lumber yards has a capability for around 200-250. The use of > >the owners key will typically remove one or two sets of balls, but the > >other three or four chambers remain MK'd. That means there is a MK that > >will operate, it just typically isn't ever made and sold to the > >contractor. > >BBE. > > > >Putyourspamhere wrote: > >> > >> If these residential locks are truely masterkeyed and you find this > >> consistently true in specific neighborhoods or from specific builders send > >out > >> flyers to every house in said neighborhood or built by said builder > >indicating > >> that you have good reason to believe the homeowners lock is masterkeyed and > >can > >> be opened by keys in the possesion of others besides the owners. Offer to > >check > >> the locks for free (if you send the flyer you should already be virtually > >> positive the problem exists) then re-key at your regular cost, or sell them > >> better locks altogether. You could make a killing and solve a real security > >> problem for lots of people all at the same time. > > > > It sounded as though the poster was talking about locks that were strictly > masterkeyed with no construction keying at all. Therefore the use of the > homeowners key would have no effect on the ability of a previously distributed > contractors key, in this case a master, to work the lock. Maybe I misread and > he meant a lock with both construction and master keying.

Yes, of yourse this is not the best way to do thing, but the discussion slightly drifted to a general "masterkeying is evil" :) Whenever possible and convenient, I use my own locks and not the ones I found in place...
regards - Ralph

That's fine and well. I was speaking in context of this thread when I said there is no upside for the homeowner with masterkeying. Here the master or potential master being for different houses with different owners. Obviously if a homeowner wants all their own locks master keyed that could be quite convenient for them.
Ah, but it is done. All the time.
Agreed.

In a lock with master pins in addition to the constuction keying feature thats not true.
It is in some places. Also important is that in practice all the balls frequently are not trapped in the divits in the plug when the homeowners key is first used. Often they are never all trapped even after many uses.
I have seen many Kwiksets that were construction keyed, and actually now that I think about it they all also had master pins. They are commonly used by builders of low to mid range housing around here.
No one said it is. What has been pointed out is that the two are frequently used in conjunction with one another.
It "needs to stop"? LOL.

Sorry if it came across that way. I was speaking only in the context of this thread.