I would like to find a piece of Brunel's broad gauge rail, known as 'bridge' rail or 'top hat' sometimes found supporting fences or notices. I suppose a battery powered angle grinder and a quiet night would be essential.
Lots of 'ifs' there? None of which apply to me.If I had to cut something like that I'd take it to a local engineering workshop & ask them to put it through their bandsaw.
I was in a hydraulic cylinder repair place & they would cut the pistons out of hydraulic cylinders in their band saw.
I can't part off hydraulic piston material in my lathe because its just too tough. Not even with carbide inserts. That's even after I've ground the chrome plating off.
But they can saw it.
Metals Supermarket might do it for you as well if you ask nice.