tap and die set?

[Floyd Mah]

Try this site. www.mcmaster.com
They sell high quality taps. Look at this page: http://www.mcmaster.com/#taps/=3ov173
It explains the different types of taps. If you have a thru hole in a plate, a spiral point tap will work really well. I've used these both with and without backing up. Also depending upon the thickness of your workpiece, you might even be able to drive it with a power drill, although I wouldn't do it in a piece that was critical or irreproducible. Besides lubrication, the most important thing to do is to drive the tap in squarely. Torquing the tap off the axial direction is the most likely reason that a tap will break. One way to prevent this is to drill a hole in a wood block vertically that will guide the tap in and start the tap with the block clamped in place over your workpiece. The "H" number specifies how loose the resultant threads will be relative to the intended screw. The usual spec is H3. An H2 tap gives you a tighter fit. The coated taps, titanium nitride, are only slightly more expensive, and seem to cut very smoothly. The number of flutes affect the number of cutting edges but also might mean a tap has less metal (and hence strength). Another consideration, mentioned by someone is how much oversized the initial hole is. The larger the hole, the lower the percentage of thread supporting the screw. Obviously, the more oversized the hole, the easier it is to tap the hole (less metal to remove) but you give up strength in the resulting screw hole. Consult a table of recommended clearance holes for the material you are working with. I guess before people get upset with me mentioning a power drill, I would like to say that it can be done, but only with caution, and after you have some experience, in non-critical work.

Anyway, buy the taps only as you need them because you can be assured that you are likely starting with a fresh tap or one that you know the history of, and most importantly, the quality of, relative to getting a box of taps that may be of questionable quality.

[Josh Brouse]

Well, I have done metal fabrication for years professionally, and it is easy once you get that first time over with (just like everything). i personally use a drill when tapping. but i have been doing it awhile and know the toque that they generally break at. and i know my drills settings well enough. with a little practice you'll be using your drill to speed up the process in no time. but just starting to get the "feel" use the little bar that's made for it.

1. use this chart to get the right drill size http://www.korit.com/tapndrill.htm

2. use a lubricant (as another has stated) I like "drill chill" but anything that qualifies will work

3. starting the threads is the "most" dificult part or the process. try and keep the tap plum as you go in. you can easily tap the hole at a angle. and the head of the bolt will then not sit flat on the head and be prone to breakage (at the head). This is one of the reasons i use a drill easy to plumb. other reason is fast!

4. as you go in you'll feel the tap get "bound up". this is the metal shaving getting to long and hitting and/or clogging the flute of the tap. as stated again you no in reverse to clear/shear that metal.

5. Now your threads are done put a bolt i right, Yes? Well, no. Debur the the mating surface for sure (small shavings may scratch and add material between the parts) and I like to debur both sides of the hole if i can reach them. I use a simple 45 degree chamfer bit. but using a larger drill will do just fine without buying something your not going to need that often.

K my rambling is done. hope it was useful

[george wilson]

How thick is the steel to tap?

[Josh Brouse]

well i figured id post a what to do if you get the tap broken off in the piece.

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scenario 1

you break the tap off a work piece that you can get to the back or the tap broke off with room at the top.

fix
easy vise grip pliers and get to twisting (tap are brittle so tighten just enough to grip and twist. more torque will just break the tap again)
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scenario 2

you now break it off in the rail and can get to the back side and have broke it off flush or nearly flush and cant get a grip with anything enough to twist it.

fix
well not hard but not easy either.

using a punch. knock the tap through and go up one size in bolt. that will require you to go up in drill & tap and redo the process again with that hole.

or

use Self-Clinching Fasteners generally called a PEM nuts. (PEM is a manufacturer)
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hope this part will not be used. but its there if you need it

good luck

[ROY DICK]

Matt,
Which ever you decide get some of this tap magic.
http://www.tapmagic.com/.
Works like cutting butter on drill bits and taps.

Roy

[Jay Jeffery]

Those items you listed and all such of that ilk that are made for the consumer were not actually intended to ever actually be used.
They will leave you crying in your beer with snapped off taps in blind holes and no way to extract 'em.

Those cheap taps are often suitable for cleaning up existing threads. If you have done any extensive automotive repairs on older cars, you will know how important that can be.