RE: 4-40 die problem
Obolel
The difference in diameter will definately affect the strength, but that was not my main consideration. Being able to cut my own threaded rods was the main consideration.
I looked at the site recommended ie: http//www.rodchuck.com/ and that absolutely looks like a very usable product that I'll be taking a further look into.
Regarding the cutting of #2-56 threads, I have been using a 2mm rod and this seems to work very well. The 2mm is .079 and the outside diameter of the #2-56 is .086, a difference of only .007. This also has worked well with never a problem. The metric size rod should be available from any good tool supply shop.
Good luck
Fred