I have a couple questions about work hardening 300 series stainless.

Does it get hard enough for something with high strain in a very limited
stretch? Something like a fish hook?

When it reaches full hardness does further working make it start to break
down and get weaker? How much further working?

Can it be carbon treated for additional surface hardness like on the point
of a fish hook?

No I am not planning to get into the fish hook business. Just thinking
about things.

On Oct 20, 11:50*am, "Bob La Londe" wrote:
I have a couple questions about work hardening 300 series stainless.

Does it get hard enough for something with high strain in a very limited
stretch? *Something like a fish hook?

When it reaches full hardness does further working make it start to break
down and get weaker? *How much further working?

Can it be carbon treated for additional surface hardness like on the point
of a fish hook?

No I am not planning to get into the fish hook business. *Just thinking
about things.

If you WANT to work-harden it, look up AISI 302.
http://www.suppliersonline.com/propertypages/302.asp

On Mon, 20 Oct 2008 08:50:16 -0700, "Bob La Londe"
wrote:

I have a couple questions about work hardening 300 series stainless.

Does it get hard enough for something with high strain in a very limited
stretch? Something like a fish hook?

Loosely speaking, strain *is* stretch -- change in length per unit
length. Type 301 can be cold worked to around 200,000 psi yield, which
is quite strong, comparable to a wrench. I don't have data on 302,
which is commonly used for SS springs, but I assume it would be
similar. Cold working a big lump, like a wrench, to that high a yield
would be much more difficult than drawing wire, if not impossible.


When it reaches full hardness does further working make it start to break
down and get weaker? How much further working?

Ductility decreases with increasing yield, so, yes.


Can it be carbon treated for additional surface hardness like on the point
of a fish hook?

It can be nitrided, but I suspect the temps involved will undo the
cold work.

--
Ned Simmons

"Bob La Londe" wrote in message
...
I have a couple questions about work hardening 300 series stainless.

Does it get hard enough for something with high strain in a very limited
stretch? Something like a fish hook?

The rule of thumb for austenitic stainless steels (300 series) is that they
can be strain hardened to around Rc 50. This is 'way too low for a
conventional carbon-steel fishhook, which runs upwards of Rc 62.


When it reaches full hardness does further working make it start to break
down and get weaker? How much further working?

The answer is yes, but the amount varies with the configuration, strain,
etc. You'll get local failure in tension where the ultimate tensile strength
is exceed. That will have the effect of weakening the whole piece, just like
bending a wire back and forth until it breaks.


Can it be carbon treated for additional surface hardness like on the point
of a fish hook?

'Don't know, but I doubt it. The chromium in the steel prevents it from
converting to ferrite or martensite at room temperature. I don't think that
adding carbon will change that, but I'm not sure. I think you also have to
reduce the chromium content.


No I am not planning to get into the fish hook business. Just thinking
about things.