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TR6 ign. key & locksmiths - locks 101

To: triumphs@autox.team.net
Subject: TR6 ign. key & locksmiths - locks 101
From: "Steve Nabors" <topdown@eudoramail.com>
Date: Wed, 09 Jun 1999 23:23:47 -0700
Organization: QUALCOMM Eudora Web-Mail (http://www.eudoramail.com:80)
Pete wrote: 
>>>>He quoted me $80 for the part.

Pete,
The trick here is that most people take their keys to Walmart and the keymaker 
takes your key with a suitable key blank and makes a "new" patterned key from 
your old worn one(no guess work, just stick the worn pattern in there and let 
it go). Bare in mind two blanks may look the same but one maybe right handed 
that the other left(looking edge on at the key as if you were seeing what the 
lock sees as the key is inserted):

right below
|
 |

left below
 |
|

I forget which is which as I'm not a locksmith. Anyway, a locksmith(as you 
said) looks at the old key and takes a guess at the original depth cuts and 
makes a truely new key(not patterned on an worn key). 

Now, this one side of the story. The other is the lock cylinder. As the key 
slips into the cylinder there are tumblers(little dowel shaped pieces of brass) 
that are different lengths. These lengths correspond to the different depths of 
the cuts in your key. These tumblers keep the lock cylinder from turning. Once 
the key is inserted, the tumblers(with springs behind them) hop into the cuts 
of the key and each one becomes flush on the surface of the lock cylinder. Thus 
the lock cylinder now has no henderance to turn.

What happened in your case is the key wore down to the point that the tumblers 
were effectively falling into deeper cuts(due to wear) and the cylinder would 
not turn(as if you put someone elses key into your lock). Only one tumbler has 
to fall too far for this to happen. You can get away with giggling the key for 
a while and then one day it happens(it just wont turn). I'm just guessing that 
the tumbler at the back of the cylinder is the one that kept you from turning 
as the leading edge of your key gets the most wear over the years as it passes 
over all the tumblers(on the way in and out). Combination locks(on lockers and 
vaults) work in the same manner but you line up a bunch of sloted disks until 
they all line up and the lock opens.

I've been offline a couple of days. That was good advice you got from Fred 
Thomas and Randall Young as had you gone the Walmart route, you'd get a 
patterned cut key which sometimes works........for a little while.

Now, the tumblers and springs and cylinder and lock cam all wear over time(just 
as your key did). At this point, you cylinder works fine. I'd leave it alone 
"till it breaks". I think the tumblers are made of a stronger(harder) brass 
alloy and thus hold up longer(thus the key takes the wear). In your case the 
lock did what it was supposed to do: It kept a foreign key from turning the 
lock cylinder only in this case it was your worn out key.

What a locksmith does to re-key locks is simply pull the cylinder and scramble 
the existing tumblers and makes a key to fit the new arangement. If you have 
locks on your car that you replaced(one door and not the other for instance), 
you can take the new lock cylinder and have them make it work with your other 
door key by doing a tumbler match up arrangement. 

If you have a lock that is more for show and not for real security you can take 
all of the tumblers out and a flat head screw driver will turn the cylinder. 
Wait a minute, outside of the ignition and trunk key, this would fit the 
description of every lock on my TR6.

I'm rambling now.........good night!



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