On Sat, 2 Mar 2013 16:19:58 -0600, "Paul K. Dickman"
wrote:


"Ed Huntress" wrote in message
.. .
On Sat, 02 Mar 2013 14:25:29 -0600, Ignoramus22609
wrote:

On 2013-03-02, Ed Huntress wrote:
On Sat, 02 Mar 2013 13:46:48 -0600, Ignoramus22609
wrote:

Ed, I am using those Starrett blades with variable teeth and they are
amazing, well worth the money. I can easily make, say, 20 cuts of 5
inch rounds on a given day, lately. The blades fly through regular
steel.

i

Aha. Well, I haven't followed this thread very well, having given up
on having any helpful ideas early on, but the previous comment about
non-austenitic stainless steel plucked a cord.

FWIW, most high-nickel steels, which work-harden like crazy, are also
magnetic. Even 304 is highly magnetic if it's been heavily cold-worked
but not annealed, as is the case with cold-rolled bars.

Grade 316 won't be magnetic even if you beat it like hell. High-nickel
tool steels will be magentic, and they work-harden.

Work hardening causes a lot of surprises. Not that I'm sure what
you're encountering, but it's something to keep in mind.


I rechecked that steel round. Despite having been told that it is
magnetic, it was not magnetic, it was 300 series stainless. The
bandsaw cut it just fine, but it took an inordinate amount of time.

i

Just to recount this situation, the long chips support the idea that
it's 300 stainless. They also suggest that your feedrate is too low.
You have to be agressive when cutting work-hardening materials.

Have you cut 300 Series on that saw before? Is this bar behaving
differently than those did, if you've done it before? If it's a
cold-rolled bar and it's not magnetic, the possibility increases that
it's 310 or 316, or one of the special-purpose grades.

Aside from the free-machining types, they're all a bear to machine,
compared to 302 or 304.

One last question -- does your saw have hydraulic or gravity feed?

--
Ed Huntress

I had a friend in college that told me that the secret to machining
stainless was "Low speed and High feed".

Yeah, I think you've said that to me before, and I try to follow it. I
run into uneven cutting, I think because of work-hardening.

And I attribute that to two things: My old South Bend is pretty
flexible by today's standards, from the bed to the tool tip. So even
when I use power feed, the feed isn't all that consistent.

The second thing is that, like most hobby machinists, I'm probably too
cautious with depths of cut and feedrates.

I should practice it but I haven't had much occassion to cut stainless
lately. Mostly, I just make repeair parts these days, for the
environment that's falling apart around me. d8-)

--
Ed Huntress


Over the years I have come to respect this sage wisdom. When combined with
"Wicked sharp" it has yet to fail me.


Paul K. Dickman