Hi Bernie,
1018 is a mild low carbon steel so not a candidate for hardening. A2 or O1 are both excellent tool steel candidates for normal clock and watch tools. A2 needs a longer pre-heat time when normalizing is a concern as well as a higher hardening temp than 01. Not that 01 is a better choice than A2 it’s just a bit easier (for me) to deal with than air hardening steels. Another decent and very easy to work with steel is the water hardening steels like W1. W2 is also excellent but a bit harder to find in the sizes that I usually need. For cutters that may be subjected to high temps. then HSS like M2 would be a much better choice. Stainless steels are in a world of there own. They are excellent and interesting steels. There are so many varieties though that it can get pretty confusing figuring out what to use when. Kind of like trying to figure out which watch oil to use where when working on a new caliber wrist watch movement with complications! 
Hope this helps,
Bob
