Paracentric Keyway

[logosys]

What classifies something as a paracentric keyway? Is the Schlage C keyway considered a Paracentric keyway?

[Romstar]

What classifies something as a paracentric keyway? Is the Schlage C keyway considered a Paracentric keyway?

paracentric
adj. 1. of or pertaining to a keyway with one or more wards on each side projecting beyond the vertical center line of the keyway to hinder picking 2. of or pertaining to a key blank made to enter such a keyway

Basically, what we are talking about here is at least two wards that in a normally straight keyway extend past the centerline of that keyway.

Because that is not normally possible without weakening the key in such a fashion as to be too delicate to use, the definition refers also to a corrugated keyway that has side wards extending past an imaginary centerline presented by the pins if such a line were bisecting the lock in a vertical fashion.

The dictionary provides one definition of paracentric that comes close to our objective:

{Paracentric curve} (Math.), a curve having the property that, when its plane is placed vertically, a body descending along it, by the force of gravity, will approach to, or recede from, a fixed point or center, by equal distances in equal times

What this means to us is relatively simple. It stands to reason, although it should not always be expected, that any keyway utilizing a projecting side ward will also utilize an opposite sideward as a balance mechanism in order to provide strength to the key. This results in the common corrugated appearance of new style keyways.

One thing you will discover is that despite the requirement for equidistand side wards, that requirement is almost never met.

Is the Schlage "c" keyway a paracentric keyway? Yes, it is but only just barely. Certainly there are much more severely corrugated and warded keyways.

The YALE type keyway is in my opinion a much more difficult keyway to pick. YALE had a wonderful tendency to curve the upper portion of their keyway. This results in an offset key, and a need to tilt your pick just to reach the pins.

Add in the way the sidewards were cut, and you have a recipe for severe facial contortions. Not to mention bent and broken picks, frazzled nerves, and one hell of a great feeling when it's over.

Romstar

[SFGOON]

Sorry to revive a dead post, but this paracentric issue is starting to urinate me off....

I'm having an inordinate amount of trouble trying to nullify this simple security feature. Does anyone know of any specialized tools or techniques that assist in countering narrow, squigly keyways? I've tried the "euro" picks, as well as a very thin hook produced by peterson. Neither have yielded significant results. Any suggestions are welcome and would be much appreceated.

[Chucklz]

What keyway are you attempting to pick? Sometimes a special tension tool for just one keyway may be jsut the ticket to giving you that slight bit of room you need. I just got a Navigator set from Brockhage which has a hook that not only is fairly slim, although I wish it were slimmer, but a very narrow tang. Even if you get a slimmer pick, if its tang is just as wide as the "normal" pick, you will run into problems. LAB picks have a reputation for being rather slim and useful in paracentric keyways, but as I have never tried them I can only just pass on the advice. What I have found useful are finely ground and polished picks, that have been extensively rounded over, as in the artful pieces produced by raimundo.

[randmguy]

Wishbone and Falle-style turning tools are a great thing for paracentric and heavily warded keyways. If you don't have them available you might try using a normal turning tool at the top of the keyway.

Picking paracentric or heavily warded locks requires only a slight change in mindset. You need to get used to working with your picks at an angle to get by the wards. This also means you want to develop some extremely fine control on your turning force. It's ridiculously easy to bend or break a pick when working on something like a Kaba PKS or a Yale. The photo on the Best website actually looks pretty tame compared to the keyway we use. I have picked our PKS locks with standard Peterson picks. It is not easy nor is it quick...But that is the one of the selling point for these locks. I don't even use security pins in our PKS cores.

I suppose my advice is to take it slow. Most of these locks are manufactured to very tight specs and the wards make it difficult for even experienced pickers to maneuver tools. This is one of the reasons I prefer Peterson picks...It's no big deal to bend the tips to a convenient angle and get just a little extra wiggle room. I would also like to mention that raimundo's Bogata picks are a great tool to try on paracentric locks. I've used the HPC computer picks on PKS locks and Bogatas beat them every time on the keyways to which I have access.

Good Luck

[Chucklz]

randmguy, do you have the best keyway that has Patented slathered over every key that looks a bit like this

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[randmguy]

We have 2 keyways. One we purchased with a property looks like your illustration. I've seen a lot of them about in hospitals recently. Makes me wonder if that patent is due to expire soon. We have a second keyway that we bought for restricted access areas...Human Resources, the vault, records storage, rare materials, etc. Its similar to that, yes. Ours has slightly more intricate wards at the top though. More like this:

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It's a true bugger to work inside...You've got to make 3 different adjustments to pick placement to lift a 9 pin to the shear line. I may never NEED to pick another one unless we get a security director who thinks that nothing is secure unless they have the only keys. Our last one dropped a ring full of them in the grass on the mall. I assume they were mowed up and mulched. HA! It was kind of fun to see the look on his face when I picked his office door to get his spare set.

It's one of the few times in my career that I've heard a Provost call anyone a doofus. I still get a warm fuzzy feeling when I think of it..."Of course he can pick the locks! He used to have to do this all the time you doofus!"

[Romstar]

You guys are going to love this, but.....

Get a medium diamond, and a medium hook. lay them on a wood block. Get a blunt cold chisel and a hammer. I know this is starting to sound bad.....

Also, get a file, you will need this. Then get some sand paper, and a sharpening stone and some oil.

Start by reducing the tang of the pick with the file so that it is as thin and narrow as you think it can be while still retaining strength.

Then, use the sand paper and then the sharpening stone to provide a very, very smooth velvet or glass like finish.

Now, it gets strange. Lay the picks down on the wood block, and pick up the cold chisel. Place the cold chisel on the lower part of the diamond, and hit it with a hammer so that you get a slight bend. The shaft, or tang of the pick will be as normal, but the tip will be bent to the left or right. I usually make one of each for left and right. Do the same to the hook pick.

You've just created a corrregated pick. Now.....

Why not do that to the tang you ask? Because you can maneuver the tip much easier than you can the entire pick.

Give it a try, it's actually quite useful.

Romstar

[Chucklz]

Romstar,

Sounds like a wonderful way to make a whole new set of picks. Also, finally a convenient way to make the slight bends in the souber style mul-t-lock picks.

Randmguy- I have found that the bogota style picks used with a small tension wrench in the bottom of the keyway works wonders on these Best keyways. I think the patent expires in 2007, but Im not sure.

[raimundo]

I think I would use that chisel befor weakening the shaft, rather than after. for medeco keymark keyways, a really good pick can be made from some piano wire. one of the base notes that comes wrapped in copper wire has a center wire of polished hardend steel. I recommend that you file and sand the cut end so it doen't cut your finger, make a loop that will fit around the bird finger, have it come over your index finger and point toward the lock, this loop on the second finger will give you good control of the direction of the tip of this round wire, extend the wire as far forward of your hand as the length of the key, and make a hook bend upward, cut it off and file and sand the tip end. This makes a very strong flexible pick that works well in convoluted keyways.

[Romstar]

Well, the chisel is blunted so that you don't acidentially cut the pick. It's used after you slim and thin the shaft so that you don't have to use a lot of force on the pick, and potentially crack the shaft of the pick. Picks just aren't meant to take that sort of abuse, and can crack when you bend them. So, the less force required, the better.

It will be more than you will exert durring picking, but enough to make the bend.

Romstar

[SFGOON]

Thanks Rom, that's exactly the sort of thing I was looking for. I'm on my way to ruin a few diamond picks. Would this technique be as effective if used on a shallow hook? All your advice is greatly appreceated, it's very nice to have mentors of this caliber.

[Romstar]

Yep,

It works on most picks. However, the smaller the tip, the more maneuverable it is naturally. I've done this trick to just about every type of pick, and gotten good results.

Some picks, such as profile or computer picks don't need this angle as often. The riffle picks on the other hand can benefit from it because you can bend the entire working part of the pick along the base so it gets by wards.

Romstar