Key Blank Thickness

Dec 10, 2004 Last reply: 21 years ago 8 Replies

I was looking at the keys on my keychain, and noticed that most of the keyblanks had a different thickness. I got out a micrometer, and noticed a pretty big range in all of the cylinder keys. Even keys of similar type (e.g., SC1) but having different makers had different thicknesses. Just a sample of some thicknesses of the keys I measured:



SC-1: from 0.085" to 0.090" KW-1: from 0.079" to 0.081" M-1: 0.076" (only measured one) Y-1: 0.081" (only measured one)



My questions are:


- for relatively common commercial cylinder keys, do most differ in thickness due to various manufacturers using different sheet thickness when stamping the keys?


- For the common blank types that all seem to seem to be within about



0.01" of each other, could a manufacturer use just one key blank thickness for all of them (e.g., use a 0.082" thickness for producing SC-1, KW-1, M-1, Y-1, etc.). Obviously, I realize that the milling would have to be different.


- Since the SC-1 had a range of thicknesses that I measured, and they all still work in schlage locks, what is the typical range of key thickness tolerance that the average lock has (i.e., on average, would a schlage or kwikset accept key thicknesses of +/- 0.05"?)



Any references you guys had to commercial literature or websites (Kaba Ilco, Kwikset, etc.) that discusses this would be much appreciated. I've looked, but haven't been able to find anything.



Regards to all.


As long as the blank is thin enough to enter the correct keyway reliably, thick enough not to enter others it shouldn't, and thick enough to retain strength, I'd say it's probably good enough. I'm sure there are official manufacturer's specs on tolerances for any given keyway, but -- especially given the temptation for second-source key manufacturers to produce blanks that will tolerate second-source locks that may not be *exactly* the same keyway -- I don't find this variation surprising.

funny you should mention that.. PERSONALLY, I think it has to do with the manufacturer of THAT lock... For instance, I was asked to rekey an SC1 lock once, NOT made by Schlage, and a genuine SCHLAGE key would not go in.. aftermarket blank would tho, made by 1 company, and not another.. methinks, they think, 'close is good enough', and run with it..

--Shiva--

I've never seen this discussed. Making aftermarket blanks a couple thou thinner makes perfect sense. They will go into the keyway OK, and won't cause any problems.

I've also not studied this, but it sure is an interesting thought.

variation

I had a customer who drove a chrysler product-he had the original keys for the car when he bought it used.He had a copy of the trunk key made at the big box. key would not even go all the way in. Did some looking around and found out that axxess had produced an intermediate blank to fit two different keyways-and didnt get it right. Cant remember the numbers on this right off-been a few years-LOL

A couple of things to consider. A brand new factory blank from Schlage might not work in other manufacturers locks that use the same keyway, but if the aftermarket manufacturer made the blank .005" thinner it would pass both, they would get less complaints and sell more keyblanks.

Also if the blank is a little thinner it will wiggle around in the plug a little more allowing the key to work a little high or low.

So tell us, why are you measuring the thickness of your keys? Do you have a lot of time on your hands or did you just buy a micrometer and had nothing else to measure?

Well the KW1 aftermarket keys here will fit the Kwikset locks but about 1 in

5 wont go all the way in a Black and Decker 199 or 200 deadbolt. BTW, Black and Decker makes Kwikset. Go figure.

There are a lot of keys floating around here that say KS1 but look like KW1 blanks. They're silver in color, have KS1 on them. The spacing is also off on those on the ones I've seen.

Thanks for all the replies. I still have a few questions, but I doubt that there is much literature on this subject.

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