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TAPPING AND THREADING TOOLS
Here are some tapping and threading
tools that will help you get your threading threaded properly.
First of all, when tapping, use a tap block. This
one was made in 15 minutes or so.
Doing so makes sure your holes are
perpendicular to the workpiece!
You can download and
print a free drawing of this tap block. It takes only 15 minutes to
make. |
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There are many two basic types of thread creation: cutting and forming. For most of us, we use the cutting method (using taps, dies, and other cutting tools) to make threads.
For most hand operations, you can use a standard 2, 3, 4, etc. fluted tap of the bottoming variety (which has threads all the way to the tip) or tapered versions:
If you're going to tap under power (like you'll see below) you should use a spiral point or spiral flute tap. The former looks like the above tap, but has more of a drill point to push the cut thread ahead of the tap:
The latter sprial flute tap resembles a drill bit to pull the cut thread out like a regular drill bit:
For assisted tapping using tapping heads like the Tapmatic 30x, 50x, etc. series of heads (or from companies like Procunier), you can power tap using the spindle. The tapping head has a clutch mechanism that lets you tap downwards preventing cross-threading, and with a quick pull upwards the head will reverse and withdraw the tap without breaking. Neat huh?
Unfortunately, the more common 50X model which goes from #6-1/2" tap sizes using two rubber/metal "flex" collets won't fit in the mini-mill when combined with an ER collet setup. You would still be limited if you used a MT3, R8 or straight shank with R8 collets, but that extra 1"-2" of increased space may be all you need..
In contrast to the above Tapmatic 50X model held in place with an ER collet, here we have a smaller model Tapmatic 30X which has a #0-1/4" capacity and is much smaller in girth than the 50X. It is shown here with a standard 1/2" R-8 collet to give that much needed extra 1"-2" taken up by your ER collet system. The 1-2-3 block is shown for scale.
For many of the jobs around here, #8, #10 and 1/4" threads are frequently used, so the 30X is a wise choice for tapping under power. Note that you can use a drill gun too but this takes a bit of care if you first use a tap block to square up the initial threads and then remove the block and drill-tap as you may cross-thread your workpiece. The Tapmatic 50x (similar to the R5, TD/TC, etc. though with fewer features) is nice for making jig fixture plates and such where 3/8" and 1/2" threaded holes are used. The other advantage of Tapmatic's system is that they use a rubber flex collets that conform to ranges of tap sizes. With the 50X only two collets are required whereas with other manufacturers like Procunier, spring collets are used which requires you buy more collets for the size of tap to to be used.
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