Yes, if it's really 70mm, it would be extremely rare to be anything other than Italian, not sure I've ever seen English, French or even Swiss thread on a 70mm BB. The surest way to tell was already suggested - remove the adjustable cup and try an English adjustable cup. It will slide easily into an italian BB without engaging the threads. Now, telling French from Swiss thread on a 68mm BB shell on 60's/70's French or Swiss bikes presents a much greater challenge - been there, done that.
Jerry Moos Big Spring, TX
Steve Maas <email@example.com> wrote: Almost certainly standard Italian--i.e., right-hand--threading. If you want to be absolutely sure, look into the BB from the opposite side, and you should be able to see a few threads. This will tell you how it is threaded. Simple enough!
Steve Maas Long Beach, CA, US of A
Bianca Pratorius wrote:
> Item: 70mm shell Bianchi bb.... Frame made in Italy mid 80's Columbus
> I need to remove the fixed cup. This must be a common problem. I don't
> want to muck up the threads, but I have no way of knowing which way to
> turn the fixed cup. You can't see in there to determine which way the
> threads are running. If I make a mistake I will have damaged the frame.
> Which way should I remove the fixed cup....Normal counterclockwise or
> Garth Libre in Miami Fl.