TW

Tom Watson

12/12/2005 9:42 PM

More Than I Ever Wanted To Know About Threads - and a really cool book.

We've all bought bolts and nuts.

If you are like me, you don't think much about them.

You just want them to be long enough and thick enough to fasten
whatever needs to be fastened.

If you are like me you know about the common types of bolts and what
they are for - and you get by.

If you are like me, you probably never gave much consideration to the
threads on the bolts. They just came along with the bolts. You order
1/4-20's or 8-32's, or 3/8-16's but still don't think much about what
it all means.

I never did - until last Friday.

Last Friday I found out that we had a little bolt problem at work -
more accurately, we had a little thread problem.

The company that I work for, like many companies, orders stuff from
China.

We buy metal parts from them.

This particular part has a weldnut on it that is intended to receive a
3/8-16 stem threaded stem for a caster.

If you are like me, you think that the guy on the other end, who is to
punch and tap the hole for this common caster stem, won't really need
much more of a description than that.

Damn - assumptions are wild and terrible things.

By the time I was done I had spent three hours searching on the
internet, resulting in going to Borders to buy Machinery's Handbook
(27th edition) ($85.00) (Type smaller than the Book Of The Month
Club version of the OED) and then reading for hours over the weekend,
simply to understand the most basic terminology.

"It ain't rocket science"

Damned near is.

By the time I got done trying to understand major and minor diameters,
pitch diameter, thread pitch, thread engagement, fit classes, the
negotiation between the British Standard and the American Standard to
resolve the argument over flat bottoms v. rounded, helical degree
standards, grade bolts and the effect on relief, why square section
threads are more efficient but don't work, why Acme is not somewhere
to buy food, how metric bolts vary from lesser standards, etc., etc.,
etc. - I was plumb wore out.

I finally did learn enough to be able to write to the Chinese engineer
guy in language that I hope is acceptable to him, which quoted a bunch
of standards, engineering tables, accepted tolerances, etc., etc.,
etc., - which ultimately came down to the fact that, "Your friggin'
hole is too big and your threads fit sloppy".

But I got a cool book out of the deal.

If you work with metal, take a look at the Machinery's Handbook.

You can sit that sucker by the can for the next twelve years and not
get through it all.

And it has some great stuff in it.

(watson - who thinks he now has a handle on why the engineering boys
at college didn't go out much on the weekends.)




Tom Watson - WoodDorker
tjwatson1ATcomcastDOTnet (email)
http://home.comcast.net/~tjwatson1/ (website)


This topic has 10 replies

Ww

WillR

in reply to Tom Watson on 12/12/2005 9:42 PM

13/12/2005 7:01 AM

Tom Watson wrote:
> We've all bought bolts and nuts.
>=20
> If you are like me, you don't think much about them.
>=20
> You just want them to be long enough and thick enough to fasten
> whatever needs to be fastened.
>=20
>=20
> (watson - who thinks he now has a handle on why the engineering boys
> at college didn't go out much on the weekends.)
>=20

Pretty much sums it up -- as I recall.

>=20
>=20
>=20
> Tom Watson - WoodDorker
> tjwatson1ATcomcastDOTnet (email)
> http://home.comcast.net/~tjwatson1/ (website)


--=20
Will R.
Jewel Boxes and Wood Art
http://woodwork.pmccl.com
The power of accurate observation is commonly called cynicism by those=20
who have not got it.=94 George Bernard Shaw

bb

"bent"

in reply to Tom Watson on 12/12/2005 9:42 PM

14/12/2005 11:49 PM

sorry, i'm not thinking along the lines of presentation, but prints of
views. Lt won't draw off of a single 2D plane, and other things to begin
with. Autocad can spin all grown pieces seperately or individually in 3D,
or from any view, including the 3 normal, but its not a pick and choose
software. Nor does it create a bill of materials. Whether and how easy it
is to create accurate dimensioned prints from 3 or more views depends on
version. ProEngineer, for instance, will automatically create all printable
dimensioned views when you model the piece(S) automatically. The great
thing about this end of software is that it monitors what you have done in
terms of draw line from a to b . Create a surface from ab using point c.
Create boss from surface abc d height. When you change a b or c, d
automatically adjusts. It asks you what to do (you tell it) . In AutoCAD
if you change a, b, or c, you might as well erase anyfrom from d on that
depends on them. This is difficult software and expensive. ($10G).

Cs

"CW"

in reply to Tom Watson on 12/12/2005 9:42 PM

14/12/2005 3:05 AM


"Upscale" <[email protected]> wrote in message
news:[email protected]...
>
> "Tom Watson" <[email protected]> wrote in message
> >
> > You can sit that sucker by the can for the next twelve years and not
> > get through it all.
> > And it has some great stuff in it.
>
> Yeah, but are you going to remember enough of it to help you with
anything?
> >
>
Yes. It's my job to know that stuff.

bb

"bent"

in reply to Tom Watson on 12/12/2005 9:42 PM

14/12/2005 11:04 PM

I doubt its neccesary. Not LT. But even without 3D you can see things you
can't imagine, and keep track of a BOM. I hate LT just because of the lack
of the [Ctrl] + MBR shortcut.

Cs

"CW"

in reply to Tom Watson on 12/12/2005 9:42 PM

15/12/2005 1:52 AM


"bent" <[email protected]> wrote in message
news:[email protected]...
>
> And cabinetmakers wouldn't believe the power of AutoCAD to make their work
> simpler.
It's even better with a better program.

Uu

"Upscale"

in reply to Tom Watson on 12/12/2005 9:42 PM

13/12/2005 6:49 AM


"Tom Watson" <[email protected]> wrote in message
>
> You can sit that sucker by the can for the next twelve years and not
> get through it all.
> And it has some great stuff in it.

Yeah, but are you going to remember enough of it to help you with anything?
Stuff like that might be interesting if you need to find out details for
something in particular, but the rest of it would put me to sleep. And since
it wouldn't be the first time I'm fallen asleep on the can and woken up
sometime later with a really sore butt, I think I'd rather leave it out on
the bookshelf in a noticeable location so I can use it to impress my
friends, most of whom know more than I do.

RM

"Ron Magen"

in reply to Tom Watson on 12/12/2005 9:42 PM

13/12/2005 4:51 PM

Joanne calls that, "Camping out". And the head ". . .is NOT your dammed
library !!".

Unfortunately {or 'fortunately' as the case may be} she is a Study
Coordinator for the Gastrointerology Department . . . and arranged her
'revenge'.

Just something to keep in mind next time you 'doze off' .

Regards & Good Luck,
Ron Magen
Backyard Boatshop

"Upscale" <[email protected]> wrote in message
news:[email protected]...
>
SNIP
> it wouldn't be the first time I'm fallen asleep on the can and woken up
> sometime later with a really sore butt,
SNIP

dd

dgadams

in reply to Tom Watson on 12/12/2005 9:42 PM

24/01/2006 9:46 PM

On Tue, 13 Dec 2005 07:01:19 -0500, WillR wrote:

> Tom Watson wrote:

--snip
>>
>> (watson - who thinks he now has a handle on why the engineering boys
>> at college didn't go out much on the weekends.)
>>
>
> Pretty much sums it up -- as I recall.
>

Yep. Didn't do much on weeknights either, and
the best time to go to the Library was during
football games. Tough to have a life when you
spent it working homework problems.

DGA

bb

"bent"

in reply to Tom Watson on 12/12/2005 9:42 PM

15/12/2005 12:26 AM

I put more about CAD software under message "A CAD Question"

bb

"bent"

in reply to Tom Watson on 12/12/2005 9:42 PM

14/12/2005 1:41 AM

I bought the 2630pp 6th large print edition, which is normal sized text
after getting an honours CAD/CAM diploma. It was a special order. You can
get it &/or a CD so you can search keywords. I read it cover to cover, and
took a thousand pages of notes. Just threw them out, about 3 feet of them.
It is amazing what I can recall, from any page. When someone says you can't
weld plastic I say you can seven ways, give exact radio frequencies or types
of magnetic flux, etc., I can tell you there are 22 types of plastics, and
what variations to standard physics in analysis there is. I love those
symbols of the bottom of rubbermade containers.

And cabinetmakers wouldn't believe the power of AutoCAD to make their work
simpler.

I may just take my $5G back in trade for the book and my diploma.



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