Yeah, I'm finally getting some things made in the shop! These ones are
from the first couple of weeks - exciting to me, but it's really just a
few slots in squared pieces. I'll take the new ones home next weekend
and take some more pictures. Pics are at
http://www.xanga.com/item.aspx?user=...s&uid=38125393

Today I did a dovetail slot. It was a little hard on the nerves. Up
until this point if the mill started doing something unexpected I could
just back the cutter off while I figured out what was going on.

I'm really loving this school thing. Tonight I spent three hours
reading about iron ore, coke, blast furnaces, smelters... I'm already
itching to get back into the shop on Monday.

While doing that reading and working on some questions from our textbook
I came up with three questions... I know you guys know your stuff and
I'm hoping you can help me out.

Are all ferrous metals magnetic? I'd think yes, since iron is magnetic,
but are there any exceptions?

What is creep strength?

What's the difference between ductility and malleability? I know the
textbook answer - ductile metals can be drawn out into a wire without
breaking, and malleable metals can be pounded or rolled into shape
without breaking. But I don't know why a metal that could be drawn out
into a wire couldn't be rolled out or hammered into a shape as well.

chem





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www.xanga.com/chemgurl

Chem
Looks like a good start.

As to your questions, Not all ferrous alloys are magnetic, most
stainless steel alloys are not or only partily magnetic. Take a magnet
around the shop and try it on various alloys.
the second - go here http://www.avestapolarit.com/template/Page____2164.asp

Ductility is usually referred to metals that can be stretched vs
malleability is a compressive feature.

chem wrote:
Yeah, I'm finally getting some things made in the shop! These ones are
from the first couple of weeks - exciting to me, but it's really just a
few slots in squared pieces. I'll take the new ones home next weekend
and take some more pictures. Pics are at
http://www.xanga.com/item.aspx?user=...s&uid=38125393

Today I did a dovetail slot. It was a little hard on the nerves. Up
until this point if the mill started doing something unexpected I could
just back the cutter off while I figured out what was going on.

I'm really loving this school thing. Tonight I spent three hours
reading about iron ore, coke, blast furnaces, smelters... I'm already
itching to get back into the shop on Monday.

While doing that reading and working on some questions from our textbook
I came up with three questions... I know you guys know your stuff and
I'm hoping you can help me out.

Are all ferrous metals magnetic? I'd think yes, since iron is magnetic,
but are there any exceptions?

What is creep strength?

What's the difference between ductility and malleability? I know the
textbook answer - ductile metals can be drawn out into a wire without
breaking, and malleable metals can be pounded or rolled into shape
without breaking. But I don't know why a metal that could be drawn out
into a wire couldn't be rolled out or hammered into a shape as well.

chem






--
--------------------------------------------------------------------------

James P Crombie

Summerside Machinist
Prince Edward Island Amateur Astronomer
Canada 3D Designer

E-mail
Astronomy webpage http://www.jamescrombie.com
Rhinoceros 3D webpage http://www.jamescrombie.com/rhino/
Mirror Grinder page http://www.jamescrombie.com/pics/
--------------------------------------------------------------------------

Thanks James.

Ahh, a magnet. I'll dig one up and do that on Monday.

That link was a good definition of creep strength. I read about it in
the Machinery's handbook, but a lot of the stuff in there is still over
my head.

I'm still muddy on the ductility vs. malleability thing. If something
could be stretched out, I just don't see why it couldn't be rolled out
too, although I can see why it woudn't necessarily work the other way.
Maybe I'll have to just be happy with the textbook definitions for now
and sometime down the road I'll really understand it. Oh, wait...
Are most metals that are ductile malleable as well? Because that would
make it easier to understand...

chem

James P Crombie wrote:
Chem
Looks like a good start.

As to your questions, Not all ferrous alloys are magnetic, most
stainless steel alloys are not or only partily magnetic. Take a magnet
around the shop and try it on various alloys.
the second - go here http://www.avestapolarit.com/template/Page____2164.asp

Ductility is usually referred to metals that can be stretched vs
malleability is a compressive feature.

"chem" wrote in message
...
Are most metals that are ductile malleable as well? Because that would
make it easier to understand...

Metals in general are malleable and ductile... Maybe it would help to
think of dry or weak clay. You can press it into shape - it's malleable
- but for the life of you, you just can't pull on it at all without it
breaking up. It has no ductility.

Tim

--
"That's for the courts to decide." - Homer Simpson
Website @ http://webpages.charter.net/dawill/tmoranwms

Yeah, that's I was kind of getting at... I'm wondering if all ductile
metals are malleable, because usually if you can stretch something out
you can also press/roll/pound it into shape. All the materials I can
think of anyway, but that's really not many.

But I can understand that a malleable metal isn't necessarily going to
be ductile as well.

not even sure I'm making sense...

chem

Tim Williams wrote:

"chem" wrote in message
...

Are most metals that are ductile malleable as well? Because that would
make it easier to understand...


Metals in general are malleable and ductile... Maybe it would help to
think of dry or weak clay. You can press it into shape - it's malleable
- but for the life of you, you just can't pull on it at all without it
breaking up. It has no ductility.

Tim

--
"That's for the courts to decide." - Homer Simpson
Website @ http://webpages.charter.net/dawill/tmoranwms



--

www.xanga.com/chemgurl

On Sat, 18 Oct 2003 10:32:55 -0300, chem wrote:
I'm still muddy on the ductility vs. malleability thing. If something
could be stretched out, I just don't see why it couldn't be rolled out
too, although I can see why it woudn't necessarily work the other way.
Maybe I'll have to just be happy with the textbook definitions for now
and sometime down the road I'll really understand it. Oh, wait...
Are most metals that are ductile malleable as well? Because that would
make it easier to understand...

Consider a lead bar. You can beat it into just about any shape you
want, so it is malleable. But try to draw it out into wire, it'll break.
(Lead wire is generally extruded instead of drawn.)

Gary

Ok, I guess I'm not making sense yet. I understand that things that are
malleable aren't necessarily ductile. I can get that part. That's
pretty clear to me.

What I really want to know now: Are all ductile metals malleable as
well, and if not, why?

chem

Gary Coffman wrote:
On Sat, 18 Oct 2003 10:32:55 -0300, chem wrote:

I'm still muddy on the ductility vs. malleability thing. If something
could be stretched out, I just don't see why it couldn't be rolled out
too, although I can see why it woudn't necessarily work the other way.
Maybe I'll have to just be happy with the textbook definitions for now
and sometime down the road I'll really understand it. Oh, wait...
Are most metals that are ductile malleable as well? Because that would
make it easier to understand...


Consider a lead bar. You can beat it into just about any shape you
want, so it is malleable. But try to draw it out into wire, it'll break.
(Lead wire is generally extruded instead of drawn.)

Gary

--

www.xanga.com/chemgurl

"chem" wrote in message
...
But I can understand that a malleable metal isn't necessarily going to
be ductile as well.

not even sure I'm making sense...

I get what you mean... like concrete is 5 or 10 times stronger (or more?
I forget) in compression than tension. Of course it doesn't deform, it
just breaks.. so think of it as the yield point instead.
Conversely, a piece of string or rope can be very strong in tension, but
for the life of it won't hold any compression at all. (Of course, that's
because it's long and flexible, so nowhere near the same idea, but... you
know what I mean... right?...)

Tim

--
"That's for the courts to decide." - Homer Simpson
Website @ http://webpages.charter.net/dawill/tmoranwms

Ahh, of course... I hadn't thought of rope and string. So things that
are very flexible may not be malleable because they'll just spring back
to their previous shape? I think I'll check a book out of the library
at school on Monday and try to straighten all this stuff out.

chem

ps - nice web page. Pictured you as being older.

Tim Williams wrote:
"chem" wrote in message
...

But I can understand that a malleable metal isn't necessarily going to
be ductile as well.

not even sure I'm making sense...


I get what you mean... like concrete is 5 or 10 times stronger (or more?
I forget) in compression than tension. Of course it doesn't deform, it
just breaks.. so think of it as the yield point instead.
Conversely, a piece of string or rope can be very strong in tension, but
for the life of it won't hold any compression at all. (Of course, that's
because it's long and flexible, so nowhere near the same idea, but... you
know what I mean... right?...)

Tim

--
"That's for the courts to decide." - Homer Simpson
Website @ http://webpages.charter.net/dawill/tmoranwms



--

www.xanga.com/chemgurl

"chem" wrote in message
...
Ahh, of course... I hadn't thought of rope and string. So things that
are very flexible may not be malleable because they'll just spring back
to their previous shape? I think I'll check a book out of the library
at school on Monday and try to straighten all this stuff out.

Hmm, hadn't thought of it that way. Any inputs from Ed Huntress?
Maybe something covering titanium? Rumor has it that stuff is a bitch
to roll down...

ps - nice web page. Pictured you as being older.

Thanks.

Tim

--
"That's for the courts to decide." - Homer Simpson
Website @ http://webpages.charter.net/dawill/tmoranwms

Nothing from Ed Huntress. And I'll keep titanium in mind when I hit the
library tomorrow

chem

Tim Williams wrote:
"chem" wrote in message
...

Ahh, of course... I hadn't thought of rope and string. So things that
are very flexible may not be malleable because they'll just spring back
to their previous shape? I think I'll check a book out of the library
at school on Monday and try to straighten all this stuff out.


Hmm, hadn't thought of it that way. Any inputs from Ed Huntress?
Maybe something covering titanium? Rumor has it that stuff is a bitch
to roll down...


ps - nice web page. Pictured you as being older.


Thanks.

Tim

--
"That's for the courts to decide." - Homer Simpson
Website @ http://webpages.charter.net/dawill/tmoranwms



--

www.xanga.com/chemgurl