Great post Ohio OZ!!
If a fellow machinist can add a comment to your post:
When buying Taps and Dies (cuts the outside threads like on the bolt) spend the money to buy good quality tools. Stay away from the HF crap. These are usually made from carbon steel, are brittle, will break easily and wear out quickly. As Ohio Oz said, it's a bear to remove a broken tap. It's easier to get a broken egg back into it's shell then remove a broken tap from a blind hole. Get taps and dies made from High Speed Steel, they will be marked on the package (and on the tool) as "HSS". They will last a lot longer and aren't as quite brittle (small taps, <1/4", still break easily).
Good cutting tools can be purchased on-line from companies like MSC and McMaster-Carr. Both will sell small quantities to individuals, but shipping costs may be expensive. (I have no relationship with either company except as a customer).
I hope I didn't step on your post Ohio Oz.