School me on Torx/Star bit sizes?

[gregp]

I have 2 new bikes, and I am encountering a lot of Torx style fasteners that I have no experience with. My KTM, for example, came with a star bit that looks like it is stamped with "4.5" or "45" - and it fits the rear sprocket bolts and other important parts. Neither of those numbers correlates to standard Torx 10, 20, 30, etc..
My V-Strom has little tiny fasteners on its windshield assembly, that are smaller than my standard Torx 10 bit.
Are there different standards for these things? Japanese/European VS SAE? Am I looking at something other than "Torx" here? Star bits?... I am looking to buy a good set of bits or wrenches that fit these fasteners on my new bikes. What should I be looking for?

[keeena]

T45 is a Torx bit size and would make sense for something like a sprocket bolt.

I've never seen different standards - Torx are Torx.

[SVenpointsixtwo]

Torx sizes go all the way down to T4 or something, so the ones on your Strom are probably somewhere between T4 and T10. You can get a Torx bit set at Lowes for the smaller sizes.

[gregp]

Thanks! I did not realize that Torx had "half sizes". I found a "45" bit, and several smaller than "10". I am not fond of them, though.