I'm doing a singlespeed conversion to my old Centurion 10 speed bike. I was able to get the left side of the bottom bracket off but the right side is proving to be quite difficult.

I tried an 18" pipe wrench to no avail. The right one has two flats on the outer rim and that's it. I was looking at a spanner wrench but I'm concerned that it won 't work since this bugger is really on there.

Are the spanner wrenches hardened steel?
What are those old cups made of? I tried to drill a couple of holes in it but couldn't touch it.

I hate to spend 15 bucks on a tool and not have it work.

thanks