Bruce Simpson wrote:

I've done a lot of machining on stainless in recent years and found
that once I became accustomed to things such as work-hardening, using
low speeds and agressive cuts, it's not so bad.

However, yesterday I encountered the piece of stainless from hell.

It laughed at my M42 toolbits, rounding off the edges within moments
of contact -- no matter that I'd ground back the surface to remove
possible work-hardening, that I used good quality cutting lube, that I
had sharpened and honed the tool perfectly adn that my SFM and depth
of cut were what I normally use for SS.

Even carbide tooling doesn't cope well with this stuff (I've gone
through three inserts already when normally they last ages on SS).

I guess this is the price you pay for picking up bits of scrap from
time to time rather than buying a known alloy off the shelf.

I don't know what alloy this is but it's non-magnetic (austenitic?)
and, based on its awful hardness, certainly doesn't seem to be 303,
304 or 316.

Maybe it's not SS at all but that most elusive of all alloys --
impervium!


I think you are getting warm! It sounds like hard Chromed shafting. It
is nearly
impossible to machine, but can be ground nicely. It may look like SS, but
one giveaway to some pieces is the mirror ground finish.

Jonm

I've done a lot of machining on stainless in recent years and found
that once I became accustomed to things such as work-hardening, using
low speeds and agressive cuts, it's not so bad.

However, yesterday I encountered the piece of stainless from hell.

It laughed at my M42 toolbits, rounding off the edges within moments
of contact -- no matter that I'd ground back the surface to remove
possible work-hardening, that I used good quality cutting lube, that I
had sharpened and honed the tool perfectly adn that my SFM and depth
of cut were what I normally use for SS.

Even carbide tooling doesn't cope well with this stuff (I've gone
through three inserts already when normally they last ages on SS).

I guess this is the price you pay for picking up bits of scrap from
time to time rather than buying a known alloy off the shelf.

I don't know what alloy this is but it's non-magnetic (austenitic?)
and, based on its awful hardness, certainly doesn't seem to be 303,
304 or 316.

Maybe it's not SS at all but that most elusive of all alloys --
impervium!

--
you can contact me via http://aardvark.co.nz/contact/

On Tue, 14 Oct 2003 16:41:41 -0500, Jon Elson
wrote:



Bruce Simpson wrote:

I've done a lot of machining on stainless in recent years and found
that once I became accustomed to things such as work-hardening, using
low speeds and agressive cuts, it's not so bad.

However, yesterday I encountered the piece of stainless from hell.

It laughed at my M42 toolbits, rounding off the edges within moments
of contact -- no matter that I'd ground back the surface to remove
possible work-hardening, that I used good quality cutting lube, that I
had sharpened and honed the tool perfectly adn that my SFM and depth
of cut were what I normally use for SS.

Even carbide tooling doesn't cope well with this stuff (I've gone
through three inserts already when normally they last ages on SS).

I guess this is the price you pay for picking up bits of scrap from
time to time rather than buying a known alloy off the shelf.

I don't know what alloy this is but it's non-magnetic (austenitic?)
and, based on its awful hardness, certainly doesn't seem to be 303,
304 or 316.

Maybe it's not SS at all but that most elusive of all alloys --
impervium!


I think you are getting warm! It sounds like hard Chromed shafting. It
is nearly
impossible to machine, but can be ground nicely. It may look like SS, but
one giveaway to some pieces is the mirror ground finish.

Jonm


It could be a chunk of Inconel.

Gunner

"You cannot invade the mainland United States. There would be a rifle
behind each blade of grass." --Japanese Admiral Isoroku Yamamoto

Or something like A-286. Rather nasty being 25% nickel IIRC. It can be
rather indifferent to tooling if one attempts to run it just a bit too
fast. Almost certainly, whatever it might be, sounds like something I
put in the category of "gawdawfulsqueaky****".

michael

Maybe hastaloy....shudder.

Les

On Tue, 14 Oct 2003 16:41:41 -0500, Jon Elson
wrote:



Bruce Simpson wrote:

I've done a lot of machining on stainless in recent years and found
that once I became accustomed to things such as work-hardening, using
low speeds and agressive cuts, it's not so bad.

However, yesterday I encountered the piece of stainless from hell.

It laughed at my M42 toolbits, rounding off the edges within moments
of contact -- no matter that I'd ground back the surface to remove
possible work-hardening, that I used good quality cutting lube, that I
had sharpened and honed the tool perfectly adn that my SFM and depth
of cut were what I normally use for SS.

Even carbide tooling doesn't cope well with this stuff (I've gone
through three inserts already when normally they last ages on SS).

I guess this is the price you pay for picking up bits of scrap from
time to time rather than buying a known alloy off the shelf.

I don't know what alloy this is but it's non-magnetic (austenitic?)
and, based on its awful hardness, certainly doesn't seem to be 303,
304 or 316.

Maybe it's not SS at all but that most elusive of all alloys --
impervium!


I think you are getting warm! It sounds like hard Chromed shafting. It
is nearly
impossible to machine, but can be ground nicely. It may look like SS, but
one giveaway to some pieces is the mirror ground finish.

Jonm

Got me. I did get some SS that seems to have rocks in it from a
dumpster. The other stuff seems to be fine , but makes me wonder why
they tossed 20' lengths of SS.

BTW, I stopped by that dumpster today and it was gone along with the
lazer stuff in the shop. The doors were wide open and not a machine
in sight. There is another building behind that , that the same guy
owns , but there was a cop setting right by where the dumpter sat and
I didn't want to look around to much. Wonder if the biggest machine
shop in town folded . The guy had given me a complete tour of the
place and I only saw two vertical mills the rest where CNC and cool
bolt makers that heat them up with elec. Time to find the guy , but
I'm busy.

Anyhow, lost my best dumpster diving place even though some of the
stuff should be in the dumpster.

On Tue, 14 Oct 2003 16:41:41 -0500, Jon Elson
wrote:

I think you are getting warm! It sounds like hard Chromed shafting. It
is nearly
impossible to machine, but can be ground nicely. It may look like SS, but
one giveaway to some pieces is the mirror ground finish.

It's not hard-chromed, I cut it to length and even a facing cut just
knocks the tooling about something awful.

I don't think it's one of the high-nickel alloys either. I've
machined a little Inconel before and although it's nastier than 316
stainless, it's nowhere near as bad as this.

I'm glad I didn't try to mill any of it -- it would have trashed my
cutters in no-time flat. At least on the lathe I was able to regrind
the tooling until I figured I was wasting my time.

Could it have been drawn or rolled so as to make the whole thing
work-hardened right through perhaps? In that case, would annealing it
make any difference -- does annealing relieve work-hardening?

--
you can contact me via http://aardvark.co.nz/contact/

In article ,
ess says...
On Tue, 14 Oct 2003 16:41:41 -0500, Jon Elson
wrote:

I think you are getting warm! It sounds like hard Chromed shafting. It
is nearly
impossible to machine, but can be ground nicely. It may look like SS, but
one giveaway to some pieces is the mirror ground finish.

It's not hard-chromed, I cut it to length and even a facing cut just
knocks the tooling about something awful.

I don't think it's one of the high-nickel alloys either. I've
machined a little Inconel before and although it's nastier than 316
stainless, it's nowhere near as bad as this.

I'm glad I didn't try to mill any of it -- it would have trashed my
cutters in no-time flat. At least on the lathe I was able to regrind
the tooling until I figured I was wasting my time.

Could it have been drawn or rolled so as to make the whole thing
work-hardened right through perhaps? In that case, would annealing it
make any difference -- does annealing relieve work-hardening?


Armco Nitronic 50 or Nitronic 60 is another possibility.
It's non-magnetic, very tough, and nasty to machine. It's
often used for pump shafts in corrosive media and for prop
shafts. It's been a long time, but I think recommended
cutting speeds are about half that of 304/316.

Ned Simmons

In article , Bruce Simpson
wrote:

On Tue, 14 Oct 2003 16:41:41 -0500, Jon Elson
wrote:

I think you are getting warm! It sounds like hard Chromed shafting. It
is nearly
impossible to machine, but can be ground nicely. It may look like SS, but
one giveaway to some pieces is the mirror ground finish.

It's not hard-chromed, I cut it to length and even a facing cut just
knocks the tooling about something awful.

I don't think it's one of the high-nickel alloys either. I've
machined a little Inconel before and although it's nastier than 316
stainless, it's nowhere near as bad as this.

I'm glad I didn't try to mill any of it -- it would have trashed my
cutters in no-time flat. At least on the lathe I was able to regrind
the tooling until I figured I was wasting my time.

Could it have been drawn or rolled so as to make the whole thing
work-hardened right through perhaps? In that case, would annealing it
make any difference -- does annealing relieve work-hardening?

--
you can contact me via http://aardvark.co.nz/contact/


Could it be a cobalt alloy?

On Wed, 15 Oct 2003 05:56:44 GMT, Ernie Leimkuhler
wrote:

Could it be a cobalt alloy?

Not impossible I guess -- it came from a large industrial plant but I
don't know what it was being used for before I got my hands on it.

I've given up actually using it for anything (other than destroying
perfectly good tooling ;-) , but the challenge of identifying it
remains.

--
you can contact me via http://aardvark.co.nz/contact/

"Bruce Simpson" wrote in message
...
On Wed, 15 Oct 2003 05:56:44 GMT, Ernie Leimkuhler
wrote:

Could it be a cobalt alloy?

Not impossible I guess -- it came from a large industrial plant but I
don't know what it was being used for before I got my hands on it.

I've given up actually using it for anything (other than destroying
perfectly good tooling ;-) , but the challenge of identifying it
remains.

I had a like experience several years ago when an old friend needed a part
made from "stainless". He was employed at the huge open pit copper mine in
Utah, from which he brought me a piece of stock he claimed was stainless.
My experience in cutting that material parallels yours. I've cut most all
of the metals, Hastalloy, A 286, you name it, including titanium, but I've
never experienced anything like this stuff. I have no idea what it is or
was, but I think I still have the rem somewhere in my storage. I hope to
never see it on the machine again!

Harold

"Bruce Simpson" wrote in message
...

I guess this is the price you pay for picking up bits of scrap from
time to time rather than buying a known alloy off the shelf.


Next time you might bring a file with you......you could also check to see
how easily you can dent it by whacking a corner of it with a fairly sharp
edge of another heavier piece of metal (concentrates the impact.)


I don't know what alloy this is but it's non-magnetic (austenitic?)
and, based on its awful hardness, certainly doesn't seem to be 303,
304 or 316.


I usually buy "drops " ( some places call them "rems" ) from the steelyard
or from a bigger machine shop when I need small quantities... While you cant
usually get material certifications from this source, the guy running the
saw typically remembers what material each piece in the drop box was cut
from.......and often the color code was left intact.


--


SVL

Bruce Simpson wrote in message . ..
Bruce,
Since you are in New Zealand maybe it has to be run clockwise :-).


Remember, The early bird gets the worm BUT it's the second mouse that
gets the cheese
George

"Bruce Simpson" wrote in message
...
On Wed, 15 Oct 2003 05:56:44 GMT, Ernie Leimkuhler
wrote:

Could it be a cobalt alloy?

Not impossible I guess -- it came from a large industrial plant but I
don't know what it was being used for before I got my hands on it.

I've given up actually using it for anything (other than destroying
perfectly good tooling ;-) , but the challenge of identifying it
remains.

Heck, maybe you should trying to make it INTO tooling?

--Had to machine some components once out of something similarly
nasty. The stuff had been annealed B4 I got it (supplied by the customer);
but was still extremely nasty. Might you have a go at annealing it and try
again??

--
"Steamboat Ed" Haas : Screw the governors...
Hacking the Trailing Edge! : Recall that $87 billion!!
http://www.nmpproducts.com/intro.htm
---Decks a-wash in a sea of words---

Just looked it up and the machinability rating on Nitronic 60 is 23%

I assume this is relative to carbon steel

Any chance it is 17-4 or 17-6 precipitation hardened stainless?

Koz

Ned Simmons wrote:

In article ,
says...


On Tue, 14 Oct 2003 16:41:41 -0500, Jon Elson
wrote:



I think you are getting warm! It sounds like hard Chromed shafting. It
is nearly
impossible to machine, but can be ground nicely. It may look like SS, but
one giveaway to some pieces is the mirror ground finish.


It's not hard-chromed, I cut it to length and even a facing cut just
knocks the tooling about something awful.

I don't think it's one of the high-nickel alloys either. I've
machined a little Inconel before and although it's nastier than 316
stainless, it's nowhere near as bad as this.

I'm glad I didn't try to mill any of it -- it would have trashed my
cutters in no-time flat. At least on the lathe I was able to regrind
the tooling until I figured I was wasting my time.

Could it have been drawn or rolled so as to make the whole thing
work-hardened right through perhaps? In that case, would annealing it
make any difference -- does annealing relieve work-hardening?




Armco Nitronic 50 or Nitronic 60 is another possibility.
It's non-magnetic, very tough, and nasty to machine. It's
often used for pump shafts in corrosive media and for prop
shafts. It's been a long time, but I think recommended
cutting speeds are about half that of 304/316.

Ned Simmons

wrote:
Maybe hastaloy....shudder.

Hastelloy / Alloy C-276 is not _that_ difficult to machine..
Just slow cfm, enough feed, and things are ok..

Kristian Ukkonen.

Not quite the same, but recently I cut some small parts out of some
7-17 ph stainless and tried to silver solder them. After that did not
work, I looked in some reference material and found that regular
silver solder is not recommended for 7-17 ph. Naturally the local
welding supply shops have not heard of more than one kind of silver
solder. I remade the parts out of other material.

Dan

On Wed, 15 Oct 2003 19:32:46 +1300, Bruce Simpson
wrote:

On Wed, 15 Oct 2003 05:56:44 GMT, Ernie Leimkuhler
wrote:

Could it be a cobalt alloy?

Not impossible I guess -- it came from a large industrial plant but I
don't know what it was being used for before I got my hands on it.

I've given up actually using it for anything (other than destroying
perfectly good tooling ;-) , but the challenge of identifying it
remains.
Should be forgable if you wanted to ahve a go at it. If you are ever
coming up to Civilisation again, throw some into the car adn I will
give it a try. might be ok for tools or something...
Geoff