It is hard to tell from your posts whether that information was all you needed, or whether more discussion of the pros and cons of bushcraft knives might be helpful. The thought that ran through my head was that when I was researching different blade steels I almost automatically got a good idea of what makers were using which steel, so your statement that you had done research, followed by your question about who uses the most widely used tool steel in the UK, was a little confusing.
While it is easy to tell you to go look on British Blades and find someone who hand makes knives, and that they will almost undoubtedly use O-1 for some or all their work, that may not really be giving you all the information that you might need. Hence my question about what kind of knife you were looking for.
Just a good all round quality bushcraft knife really
...doesn't help all that much
What I meant was:
Do you want a full flat tang, or would you be happy with a hidden tang or stick tang?
What is your preference for handle material and method of attachment?
Do you want a Scandinavian type single bevel edge, or something that is flat/secondary bevelled or convex ground?
What blade thickness do you demand?
What price range are you looking at, what is your budget?
Also, what level of experience do you have with using a knife and caring for one, ie, sharpening and protecting from corrosion?
Do you know what kind of tasks will predominate your use, hunting/cleaning game and food preparation + utility, or more wood craft and carving?
For instance, if you are not prejudiced against hidden tangs, like wood handles,
would like a Scandi bevel, prefer thinner blade stock (less than 3.2mm), are hoping for something under £75 and want something that will be used for wood work, and a little game and food prep, but mostly wood carving, then the Kellam Wildfinn Puukko might fill the bill nicely.
http://www.heinnie.com/a22gqh9455/Knives/Kellam/Kellam-Puukko/p-92-205-1241/
In fact, lots of the Scandinavian knives would do. The fact that they are not made of O-1 is not a problem.
