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Sunworshiper
 
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Default resource for tapping and die-ing

On 4 Jul 2004 07:57:46 -0700, jim rozen
wrote:

In article , Gunner says...

Your tacky offer of "thanks in advance" ...


Somebody **** in your cornflakes?


Isn't somebody going to give this guy a reference to a book
like moltrecht, or maybe that MIT web site on machining?

Really one only needs to know a few things to use taps and
dies.

1) start out using the cheapest ones you can. Because
you break a bunch of them.

2) then carefully read the tap drill diameter tables in
the Starrett catalog, and realize that the tap drill
diameter is much bigger than the minor (root) diameter
of the thread. You can get away with 50 percent threads
if you are tapping nobendium or whatever.

Then go and buy the *best* possible taps and dies after
that, greenfield or sossner.

Really what he wants to know is more about thread cutting
and thread forms in general. I tend to glean most of that
information from older books found in yard sales or used
bookshops. Thread cutting and thread forms haven't changed
in ages. This really tends to be sort of technical
archeology and allows on to spend afternoons reading books
with photos in them of machinists wearing stripey aprons
and skimmers, running flat-belt driven machinery. But
you do learn the terminology which is half the issue,
like minor diameter, major diameter, tap drill size,
the various types of taps, etc.

At first I though 'god, everyone just *knows* how to use
a tap and die.' Then I thought back to my first time, when
I busted three taps off quite neatly in the same brass buss
bar in one of my first summer jobs. Then the boss patienty
took me aside and said, "here, you do it like this...."

The term "thanks in advance" is really a very common
business letter closing.

Jim


The second to the last paragraph is what I was thinking and then I
first looked , and it turns bad. I had basically gave up on the simple
questions cause ya'll usually cover about everything. More than I know
and why bother when it will get over kill from people that do this
stuff all the time and can describe it very effectively.

Reminds me of that ahhh Tim W. thread about who has a good eye. And
this kid in my shop.

The kid wants to chase threads on his bike and I tried to help and he
said he knows what to do. He screwed up the bike. Had no idea about
TPI or anything , but thought plain determination would do.

Troll or plain asking , I don't know. Sometimes you just have to go
for it and get it perpendicular by hand. Which gets to Tim's thread.
There are a lot of people that can't handle a blasted picture on the
wall.

I don't have a lot of books or tools , but I've never seen in print
how to start them straight by hand. I just look back and forth at 90
degrees. And never crank on them , back off and clean off , and oil
kind of stuff.

Sure he didn't describe how in depth and I know it can get down right
technical , but ya'll missed the simple stuff.

Where does thanks in advance and afterwards fit in?
He maybe right , will the OP come back?