Since the material I need to tap is only 1/8" thick and will be through tapped, what about using self tapping screws to create the threads? Those are much less costly than the taps and though they might only be good for one or two threads, they might be more cost effective in this case. Thoughts?
Self tapping screws in my opinion are only good for holding sheet metal on a barn. I would not use them to many fine model or even a machine tool.
This is prett much repeating what has already been said but here are my suggestions.
1. Buy quality HSS taps. If not HSS the new super composite materials might work. For small threads we two flute taps. Never buy or use plain carbon steel taps as they seemingly are bottom of the barrel quality no matter who makes them.
2. Always use plenty of lube suitable for the material being tapped.
3. As others have noted tap alignment is critical. Most people need a tapping aid. However a taper tap can be helpful in unaided tapping.
4. Contrary to many posts here do not use a drill press chuck for tapping of the extremely small tap sizes. It works fine for larger sizes but there is too much inertia in most drill presses for this to work well for small taps. The cut off for me and my drill presses is about 8-32, anything smaller is a problem. However a tap follower in a drill press guiding a tap handle is a good idea.
5. Speaking of tap handles, most are way too big thus not allowing the feel you need. In many cases what you really need is a knob on the tap of one inch or less in diameter. Such a knob is a good lathe project! Make sure it is equipped to allow a tap follower.
6. I’m not a big fan of drilling over sized holes for the taps. There is some leeway but I really don’t like going to far below 70% thus would tend to stop at 60%. Shave too much cut off and you can have issues with fasteners that may be at the lower limit. This especially with finer threads.
7. By enlarge the majority of tapsive broken over the years are a direct result of being in a rush or trying to get more threads than the tap or hole allows. The real trick is to be able to stop yourself when you mind isn’t right for tapping. If dinner is on the table, go to dinner and leave that last hole for another day. Often it is the guy in the mirror and not the tap that is the problem.
8. You mentioned Vermont American. I can’t speak to all of their products but the majority of the big box hardware store offerings are crap. Actually anything the big box store carry seems to be crap. Recently though some of the local stores seem to be putting in the effort to upgrade cutting tools with higher quality tools. For the most part though shopping at the big box hardware stores for taps and dies is a waste of money and time.
9. If you are in a situation where a tap follower can’t be used consider tapping blocks. They can be wonderful as a tapping aid. Building a tapping stand is an alternative but it isn’t mandatory. From my perspective the real reason to build a tapping stand is to make it a platform for multiple uses. Otherwise tapping aids can be extremely simple, as simple as a V groove milled in a block of material. That material can be a piece of hardwood in a pinch. The goal is to support the tap square to the bore. The blocks with the V groove have a huge advantage in that you can see what you are doing, tapping blocks cover up the working end of the tap.
10. Instead of using the chuck of a drill press or mill for that matter, consider using it as a tap guide. Adjust the jaws so that the tap shank just slips. Then use you fingers to spin the tap in started square. Very small taps will start with a finger grip on the shank while larger ones will require something to grip the shaft. This is a good place for those tapping knobs described above.
Best of luck.
