I think it's called a Torx bolt anyway, it's the star-shaped one. I'm terrible at this stuff but need to buy a new multi-tool and could do with one with a Torx screw that will fit my headset if possible.
If it helps any, it's like the ones in the image below:
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Sounds like a Torx. It's probably a T25. Good guide to sizes [url= http://en.wikipedia.org/wiki/Torx ]here[/url]. If it's a T25 let me know and I can post you one.
Cheers Shaggy, it's definitely a Torx bolt anyway after looking at that link. T25 sounds like a good bet, I'll have a look at some multi-tools and see if any come with a couple of Torx wrenches in that range.
Thanks for the offer of postage, I have the bolt though- I think I should have said 'wrench' rather than bolt in my first post if that makes sense.
No bother. Hope you get it sorted.