Ed, there's so much here already for you to digest, but I still want to add a thing or two.
Regarding taper taps, I keep one in every size. The long tapered end does help in hard materials. It's a personal choice, just like everything else in my/your/everyone's shop.
The three types of regular taps we use in the U.S.A are taper, plug, and bottom. In the sizes I use most, which are 2-56, 4-40, 5-32, 6-32, 6-40 and 10-32, I keep all three types, and multiples of many.
If I'm tapping to the bottom of a hole in a small tap size, I start with a taper tap and go until it reaches bottom. Then follow it with a plug, then bottom tap. That's just how I do it when tapping steel, and I rarely break a tap, (but it does, and
will, happen!).
I looked at the links you posted, but didn't find any mention of where the taps are made. So, I wouldn't buy them. I buy from Enco, mostly, and some things from MSC. Try those, and the other places our fellow members mentioned. It's hard to stress how important it is to get good taps. Scrimp on dial indicators by buying the Chinese products, but don't trust them for taps. Sorry, but their quality on that particular product is still not up to snuff.
There are some good taps from other countries, and I don't mean to demean those makers. I have bought a few import taps from Enco for certain uses, and it so happened that most of them were from Poland or Macedonia. Both were as good as the ones that are marked U.S.A., as far as I could tell. The thing is some of the import ones will be from China, and they are not good, and you never know what maker you are getting when you buy "import". No other way to put that.
If you are watching your pennies while tooling up your shop, like many of us have to do, then buy a set of plug taps in the sizes you think you will need, and add to your tap collection as you need them. Buy a new tap or two each time you make a parts order, and soon you will have a full set of all types.
Here is another good place for taps. Read the short paragraph at the top of the tap section for a quick insight to what they think about the taps you need. (They agree with other folks here, that taper is rarely needed.)
http://www.americanmodeleng.com/id19.html
I don't know where their taps are made, but I would trust them to send you a good product. Their prices are in line with the larger companies, too. Really good folks to deal with.
I haven't tried "gun" taps. Something I will have to try one day. I get stuck in what ever groove works for me and tend to stick with it, so am still using the regular style taps.
Shred, I've found the same strange pricing for taps as you mention. The only thing I can think of is the simple supply and demand thing. 4-40 and 10-32 are probably bigger sellers.
Stan, what you said about the "NASA" thing is a good example of what I mean about there not being any desperate need to know these things. The "h" numbers are just manufacturers tolerance marks, and don't really apply to us modelers. You can buy a tap with any "h" designation, tap your holes, and your fasteners will fit. Usually, h2 is commonly found in all sizes from 1/2" down. When you get really small, like double and triple 0 sizes, you may only find h1. Get what ever is available for the size you want.
There is one consideration to think about, though. When you buy small taps, the lower the "h" number, the less work the tap has to do. Higher "h" numbers mean the tap is cutting the hole to a larger tolerance range, which means it is removing more metal. Does that make sense?
Dean
(keeping it family friendly)
