Key/Lock Questions

I've got an interesting project in mind. I have a 1979 Porsche 928 whose ignition keys are on their last legs. I have one (relatively) unworn key kept in reserve with the idea that it could be used as a master for making duplicates. The locks all seem to be in good condition, as the one good key operates all of them easily. But I don't want to start using this last key, as once it is worn out, that'll be the end of making a duplicate with a pattern copyer. However, due to the 'strange' design of old Porsche keys, no local locksmiths can duplicate these on standard equipment. The cost of having a new key made from the VIN number, or by a specialty locksmith is on the order of $150 to $200.

Although the keys are of an unusual configuration, they don't appear to be that difficult to make on a mini-mill. I can measure the one good key and probably make a workable copy. I'm guessing that key tolerances can't be terribly close. My worn keys are visibly different from the good one (10 to

20 thousandths off, I'm guessing) and still 'sort of' work. Even high security locks (Medeco) have been hacked by people with a photo of a key, a piece of stiff plastic and an Xacto knife. So we're not talking precision here.

What would help (if its available) is the manufacturer's specifications for the key blank and pin heights. I'm not a locksmith, but I'm guessing that the pin heights are set by some integer value times an offset in mm, or based upon a lookup value. If I had this, then I could correct my measurements to the nearest correct spec value. Otherwise, I'll just cut the key to my measurements.

So, my question is: Where might this info be available? I understand that high security lock manufacturers don't release this kind of info on a non-restricted basis. But I'm guessing that a 1979 auto isn't exactly the same as a safety deposit box.

Any other advice would be appreciated as well.

Reply to
Paul Hovnanian P.E.
Loading thread data ...

Contact Torrance Lock and Key. The owner there can answer your questions and more.


Reply to
John R. Carroll


suggest posting this in the 944 newsgroup or the 928 newsgroup - I've had no problems having keys made for an 84 944, an 95.5 944, an 86 944, and an

87 944, but I haven't tried anything pre-80s in that series. I've also had no problems with my 356, but that is maybe "too old".

be sure to oil the door handles - you won't be happy if the mechanism inside the handle fails.

Reply to
Bill Noble

In other words none of the folks you have gone to so far are very knowledgeable. ANY key can be cut, maybe you need a manual machine, a hand press or even a key file to cut one but a good smith can cut that key.

Does it use the same key for ALL locks on the vehicle? If yes you could remove one of the least used locks (passenger side or trunk lid are usually MUCH less worn than the ignition switch) Now take THAT lock to a locksmith and have them cut your new keys to fit it. The catch with this is that SOME manufacturers don't use ALL the key cuts for those locks. That is easy to determine and the smith could cut those locations based on your "good" key.

Actually they are simply cut pins. They vary in length by a set value depending on the locks manufacturer. What will trip you up is that some use special diameters OR mushroom pins. The common pins are .003 or .005 based.

formatting link
have your blank, if not I would bet you can get a blank that will fit easy enough.

Reply to
Steve W.


Right. Every local locksmith has quoted me in the $150 to $200 range. According to the local Porsche club, they just send the job out to one of a few outfits with the specialized cutting equipment. I could do the same. Or send my VIN number to the factory for a similar price.

Nope. The cuts are made at 45 degrees to the side of the key. The depths of the cut at each position vary such that each pin is depressed both vertically and laterally. Or there's a pin facing each side of the key at that 45 degree angle.

Blanks are about $30 each online. Its the cutter that is hard to come by.

I suppose this seems like a lot of work to go through to save $150. But then if I applied that logic to every project I've undertaken, I'd never have bought my first tool.

Reply to
Paul Hovnanian P.E.

Paul I am a locksmith, and I have the blanks and the equipment to duplicate these keys. Our regular price is $40 each.

Our shop is in Sacramento, CA.

Reply to
Roger Shoaf


per this note:

formatting link
I'm willing to bet the 45 degree cuts are clearance to fit the hole and that there are pins on one side only.

alt.locksmithing is as good a place as any to ask.


Reply to

You must have a bunch who look at that blank and see Porsche = Money instead of key + blank + cutting = Happy(repeat?)Customer

Doesn't change the type of pins, just the location in the cylinder. Not a problem, You only need a machine that can have the blank carriers adjusted. Not real hard.

Buy the blanks and a set of key files and cut them by hand. I have cut more than a couple keys by hand. Great skill to have.

Reply to
Steve W.

On Sun, 15 Feb 2009 12:27:25 -0800, the infamous "Paul Hovnanian P.E." scrawled the following:

I've driven a nice little 928 on the freeway at 125mph and it was a true joy to drive. They were Porsche's best vehicles. The rest are just oversexed VWs.

Well, 10 to 20 thou can be a hefty distance for shear-pin movement, which tumbler pins are. I did the Belsaw locksmithing course back in the early 80s but they didn't have that type of key available in the course way back when.

You could likely measure the depths on the master/unused key with a small ball bearing, Paul.

So no local locksmiths were able to help? Are you able to find actual blanks for it, or are you considering making one from scratch? Will you be using januwine German Billet Brass for it?

I doubt that Porsche would even give you the time of day, other than possibly saying "Oh, just buy a new Boxster and throw that old relic away." Pffft!

If you are able to talk to a local Porsche guy (better yet, a mechanic), maybe they can tell you who does keys for that dealer.

-- I'm still waiting for another sublime, transcendent flash of adequacy. --Winnie of RCM

Reply to
Larry Jaques

I can find the blanks online. And I have found outfits that will duplicate a key (none locally in the Seattle area). I just thought I'd like to take a crack at making one myself.

Having the actual dimensions in hand would help in producing a better product.

Actually, they are pretty good at supporting vehicles of that era (and older).

They send them out.

Reply to
Paul Hovnanian P.E.

Nope. I addition to the 45 degree chamfers shown on the keyhole cross section, the cuts made for the pins are made on each corner of the key at 45 degree angles.

The result is a set of ridges that not only vary up and down (like they do on a standard house key) but, when viewed from the top, from side to side.

Thanks. I'll give that a try.

Reply to
Paul Hovnanian P.E.

O.K. From a VIN number, they are charging for the cost of the books in which they look up the key codes.

What do the Porche keys look like? A friend has a Lexis, and the keys for that are a wandering groove down the middle of each side. Those are obviously more difficult to cut on a standard duplicator. The optimum thing would be a small CNC mill and a program describing the key's cut.

Standard pin-tumbler licks and keys only care about the bottom of the 'V's. The peaks don't matter at all, as the bullet-nosed pins all rest in the bottom of those 'V's. It is possible to file off the peaks and have an almost smooth key if the pin levels are close enough to each other.

IIRC, the old Yale (and other US made locks) had pins which had lengths in steps of 0.050" as could be most easily told by measuring a few "master disks" (used to make a lock work with two different heights on a single pin allowing both a user and a master key to be used.)

The Medco locks *appear* to have either pins coming in at two different angles, or with angled chisel points which will fit a normal key only when the groove is both the right depth and the right slope (left or right slope). I've never had a chance to take a Medco lock apart to verify this, however.

Does this use the usual pins and notches?

O.K. if this is a 928, a web search led me to this posting on the "Pelican Parts Technical BBS":


928 keys are cut at a 45 degree angle, and less than a dozen places worldwide have been posted in other threads that can reliably cut a key. If none of them are local to you, then
formatting link
can cut a key for you from a couple good pictures of your key. ======================================================================

It looks as though they will sell the blanks themselves, and if you have access to a key duplicator and a bit of time you could make an alternative key holder pair which would hold them at the required 45 degree angle, instead of the straight ahead angle normally used.

For the Porche, very likely. For US keys, the offset will likely be in decimal fractions of an inch.

Without a Porche key to see, I'll have to pass on how difficult it would be to make, but if the quote from the BBS above is right, the main problem is cutting the notches at 45 degrees to the key's surface, instead of the usual 90 degrees. (And the Medco ones appear to be dual

45 degrees -- alternating between right and left angles.

Actually -- is is typically a better design than a safety deposit box, which is just a warded key lever tumbler lock, albeit one with more than the usual number of wards and tumblers.

You should be able to make the typical key blank with a small horizontal miller with a stack of just the right straight and angled cutters installed on the arbor, and something to key off the cuts on the first side while you make the cuts on the second side. Once you have something which will slide into the keyway of the lock and not wobble more than your as-new key, it is then time to try cutting at the desired angles -- either with a modified key duplicator, or the same horizontal mill with very careful setup and a jig to hold the key at the needed 45 degree angle.

The depth of the cuts is typically related to the position of the grooves along the key's length, not the bottom or top edges.

What I would do, if faced with this problem is to try to pick up a Porche ignition lock of the right design, and work my way through opening it to modify it to fit your pattern key, so you can easily test the duplicates which you make without having to walk out to the Porche for each test. (Or is it kept in your shop, so the distance is short? :-)

Good Luck, DoN.

Reply to
DoN. Nichols

another good source of this kind of info is the tech discussion section of Rennlist, also pelican parts has a good tech discussion section.

Reply to
Bill Noble

Did you miss Roger Shoaf's post ? He said he has the blanks and equipment , and will cut them for you ... he's in Sacramento .

Reply to
Terry Coombs

If this were mine, Id bypass the ignition switch and put in something different


"Upon Roosevelt's death in 1945, H. L. Mencken predicted in his diary that Roosevelt would be remembered as a great president, "maybe even alongside Washington and Lincoln," opining that Roosevelt "had every quality that morons esteem in their heroes.""

Reply to
Gunner Asch

On Sun, 15 Feb 2009 19:01:39 -0800, the infamous "Paul Hovnanian P.E." scrawled the following:


Yes, it would, but copying a blank precisely would do the same thing.

Ah, the "antique" parts have higher margins, eh? ;)

I figured that, but is the locksmith local?

IAC, you'll probably have Roger make it for you unless you specifically want the experience of doing it.

-- I'm still waiting for another sublime, transcendent flash of adequacy. --Winnie of RCM

Reply to
Larry Jaques

Absolutely! A hidden switch under the dash. That is what I did with a Berkly back a bunch of years ago. Not because it was a nasty key but because all you had to do to defeat the key was reach behind the dash and squeeze the two screw terminals together to turn it on. :-) The car got stolen in Mich while I was at a short course there. ...lew...

Reply to
Lew Hartswick

Terry, you don't understand how things are around here. You have to make the first, _then_ you can buy the rest. It is the cost of education. No one likes to have their task held hostage by those with "secret" knowlege.

Kevin Gallimore

Reply to

That's a bit far away for me to be sending my last good key. And I'd like to try making one myself, just for the fun of it.

That's why I've got a workshop full of neat tools.

Reply to
Paul Hovnanian P.E.

Yanno, you can replace the ignition switch with something a bit better than what it had, instead of a bit worse...

Cole-Hersee makes replacement ignition lock and sweitch assemblies you can use, and you can armor the backside to foil the 'reach underneath and squeeze' cheat. They would have to systematically jump the circuits which is neither fast nor easy.

There are much more secure key locks available, but the hard part is rigging the contacts - they are usually 1 Amp or 3 Amp "pilot duty", meaning you have to wire up relays for everything. And add a push button for the Starter.

If you could mate a good Medeco or Ace or Best exchange cylinder to a Cole-Hersee type switch assembly, that would be nirvana. Pick resistant yet easy to install.


Reply to
Bruce L. Bergman

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.