Tubular key sizes

[Zenophryk]

So I've been looking around and there appears to be several different sizes for your average tubular lock.
I'm seeing 7mm, 7.3mm, 7.5mm and 7.8 mm. When I look at my key blank supplier they just have "tubular key blanks" no size mentioned.
In the US are there really that many sizes in use. I think the common one for us is 7.5mm. is that correct?
Anyone know a little more about this?

-Zenophryk

[billdeserthills]

A common size in the US is the key number 137. This key is made in steel and brass as many cutters don't like steel keys. Many if not most of
my tubular key customers actually bring me sizes that I cannot duplicate, as there are many tubular keys being manufactured that are restricted
or not sold to dealers. Even if they were sold to me, my crappy tubular machine will not cut them as I only have the crappiest tubular key machine
made, the scotsman now made by ilco. I also have a Herty Gerty and it won't cut but 3 sizes of these keys. I generally find that if I want to duplicate
a tubular key for a client, it can't be done, not with the equipment I currently own.

[cledry]

There are 3 commonly used tubular blanks in the US, 1 slightly smaller than the 137 and one slightly larger. Within this you can have cut in cut through the wall and some other variations. Then there are a rash of imported locks that can use almost any size key. The best machine was the old Chicago / Fort machine, it could cut almost all the varieties of US ones but was not a duplicator, you first used the machine to decode and then used the machine to cut to the decoded values.

[billdeserthills]

There are 3 commonly used tubular blanks in the US, 1 slightly smaller than the 137 and one slightly larger. Within this you can have cut in cut through the wall and some other variations. Then there are a rash of imported locks that can use almost any size key. The best machine was the old Chicago / Fort machine, it could cut almost all the varieties of US ones but was not a duplicator, you first used the machine to decode and then used the machine to cut to the decoded values.

There is also a 'mini-key' tubular key used in very small cam locks and also on computers. I can't guess how I'm supposed to cut those