Screw for the rear hanger..
 

I'm looking for what size or kind of screw that goes to the rear end of the hanger which I'm presume is for helping to align thee rear wheel. It is for an old Bottecchia road bike. Thanks for any information.

If by "hanger" you mean the flat plate with a slot for the axle, that's a dropout, not a hanger. The hanger is only the bit the derailleur bolts to.

I believe they are an M3 thread, and they're not hard to find online, just google "bicycle dropout screw" or something.

Also here. http://www.cycle-frames.com/bicycle-...H-SPRINGS.html Genuine Italian Columbus version for your Bottecchia. :thumb:

Thanks everyone. Yes Airburst I meant dropout.