Re: [CAD_CAM_EDM_DRO] Re: New guy with questions

> Do we use
> some cutting nut (opposite of a tap) of some sort?

Yes, it's called a 'die' though. You buy a tap and die set most of the time,
not just tapping. You have a tap and die wrench. The die wrench (Or stock)
is made into a shape so you have two rods sticking out that form handles to
get leverage on. In the middle where they join there is a cylinder shape you
drop the die into. The die looks like a deep cylindrical disc of metal with
a sort of clover leaf missing from the middle. Where the leaves of the
clover all joined together there is a hole the diameter of the piece to be
threaded and it's on the little protrusions (Leaf steams) that the cutting
surfaces are. The clover shape means the bits of metal can fall away and I
think it means they can just drill the cylindrical discs to rough out the
small cutting blades easily. There are two types of die that I know of, a
full die and a split die. The full die means that the die for cutting the
threads is one whole chunk of metal minus the clover leaf shape. The split
dies look much cooler though, on one side they are cut like a split washer
so if you were to pull on the sides you could pull it out into a C shape, if
you were superman. The cut goes from the outside edge and moves inward,
right into the gap in the middle, like you would make if you wanted to cut a
pattern out of the middle. You drop the die into the wrench and tighten two
set screws that grip it and hold it on place so it will cut the thread. But
if it's a split die, there is a third nut with a sharp point on it. You line
the split in the die up with this nut and tighten it so it spreads the die
open a tiny bit. Then you cut the thread and test for it's fit with the
mating component. If the fit is too tight you let the third nut out a little
and the die tightens back to it's original almost closed shape a small
amount. You pass the die over the thread again and it removes a small
shaving from the thread. You keep going until you have the thread fitting
together smoothly. My DT teacher made a joke that this is were the term to
screw someone came from. I think that was the only joke he made all year. I
am no where near up to speed with all the sizes and types of tapping
machines, threads and all the rest but that's what I remember from when were
doing them. We weren't allowed to use the taps incase we broke them, they
were thirsty days (It's bad I know).

Still Mill-less, John H.