Tap and die set. Suggestions?

I think the threads are imperial pitch but seem in vaguely decent nick apart from one eye that is clearly mangled. @danb: phwoar! shiny.

Your empire of toolness grows. You need metric and imperial of everything you buy, If you don't, you will need it, and then surely fail. Tis the way of Tool...

@bigtwin: Never hast a truer word been uttered. "Gotta catch em' all."

Wise. No-decent one will have tapered nose and straight body-all you need. Thread conversion as you describe is not possible-it will be a bugger's muddle of a bodge. You might be able to get away with it, but not a proper job by a long way. Plug is a thing you screw in to block up the hole.

When buying taps you should normally by them in 3's:

taper - for starting (its a smaller diameter than the others)
plug - is a slightly larger OD and starts forming the threads properly
finishing / bottoming chases the threads to the bottom of the hole and forms the proper, dimensionally correct thread.

Metric taps are not interchangeable with imperial.
http://www.benchnotes.com/Thread%20Cutting/thread_cutting.htm

Yes, but we're not doing holes here - it's all straight through work - BB shells, cranks and pedal holes, mudguard/rack eyelets etc.

Thats why I said normally. You'll be wanting finishing taps then.

That Clarke set posted above will be fine for bike work, save that it's not big enough to do a BB obviously.

Not for BB shells as you really need a set that clamps from both sides to align the threading:

http://www.chainreactioncycles.com/Images/Models/Full/42813.jpg

that carries these taps:

http://www.chainreactioncycles.com/Images/Models/75/42814.jpg

FUCK ME!

So am I getting this right, the clamps are £135 and the taps are £200?

£335 total?

I didn't expect them to be cheap, but seriously! I'm never going to complain about £30 BB installation again*.

*assuming it's all done well.

Italian BBs are 36 mm X 24 tpi, 70mm shell and right hand threaded.

What are my options if I want to have the threads chased? Do I need a special tap & die set and if so what is the crucial spec?

My LBS says they're lacking the right tool.

I think, but don't know, that retro di corsa is your man.

http://www.lfgss.com/member4521.html

Thanks.