Need a recommendation for a good quality metric tap set. Particularly want a 12 mm, 1.25 pitch tap. Guess I could buy just one tap but . . .. Pretty sure I won't be able to buy just taps, but dies will go with them. Thanks for any input.
Good-quality and set are about mutually exclusive. You can buy sets and you can buy good taps and dies, but the good taps and dies won't be in the sets. Make your own set. Lots of industrial suppliers online. Stick with the domestic brands like Greenfield and Chicago Latrobe unless you know the foreign-made brands. Don't forget you need metric tap and clearance drills, too. Basically, I just buy what I need when I need it. Saves having a lot of iron sitting there that I'll never use.
Haven't seen any taps OR metric hardware in an auto parts place that really begged me to take it home. Same old chink tomato can stuff you get from the likes of HF or Homier.
This has not always been the case. I've seen good sets (bought by the government and on GSA), and I got a really nice set (1-64 through
1-10) in a large (18"x 36" IIRC) metal case with fitted gray foam containing a full three-tap HSS set for each size (starting, plug, and bottoming) and a corresponding die. I got it from an eBay auction which did not have a photo, and just took a chance, going by the maker's name (TRW) and the description. It turned out to be a real deal.
Yes -- metric can mean that some of the imported brands can be the best choice. You'll pay a premium for the good USA ones.
For most of my use I prefer the gun taps (spiral point taps for being driven by a tapping head), as you don't have to keep reversing the tap to break the chips. The spiral point chases them ahead of the tap. However, for tapping a blind hole when you don't have enough metal to make an overly-deep hole to collect the chips, others are better. And in the right materials, thread forming (roll) taps are best, but require more precise (and different) tap drills.