I've been forging chisels, etc from Pandrols for a while with good results, and I got to wondering what exactly the steel was. I Googled, extensively, and got no answer. So, I just called the U.S. Pandrol office, and here's what I was told:
It's a proprietary alloy (of course), but basically a modified 5160, with perhaps a little more carbon.
I'm passing this on for those that may read it now, and for those that may Google in the future.
~D