Round Nose Finishing Tool VS Vertical Shear VS Round Insert Turning Tool VS ??? Round Shear ???

Ok, which is going to give the best finish turning 416 (or 300 series for that matter) when you have to creep up on the final dimensions in
order to reduce work piece deflection.
A vertical shear (which is what I used) leaves much better finish than the roughing tool I was using the other day on that taper, but it took 3 passes to get "decent", and I still had to spend a fair amount of time with multiple grades of emery cloth to get a smooth brushed looking finish. Its hard to creep on on too because you have to resharpen it or atleast move it up or down on the tool post atleast once in that time.
I originally ground the vertical shear to get a "better" finish on mild steel. It does that, but better is relative.
I did the usual Google searches for getting better finish results turning stainless and a "round shear" came up in one result, but the PhotoBucket virus ate the pictures so I am not sure what they were talking about. Some search for that term came up with what looks like round carbide turning inserts for wood. They also look a lot like the round inserts used on some face mills.
The other result I cam across were a few conversations about using a radius nose tool. Some argued they got great results with a veyr small radius and a large feed. Others said quit the opposite and said to make the radius nose on a finishing tool as large as you can and use a small feed. WHAT!?!?
Yeah, I have discovered the harmonic you sometimes get in the middle of a long span. For straight pieces a steady rest was recommended by some guys, but that doesn't work for a taper. One guy said he wrapped a couple lengths of chain around the work and hung a five pound weight from it. Dang-it. Wild. Note: The very light passes to finish with the vertical shear did not seem to develop the harmonic resonance, but I was turning really slow.
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wrote:

Do you mean a steady rest or a follow rest? A follow rest won't work on a taper, but a steady rest will.
However, it's unlikely that a steady rest would work in your situation, because you can't turn past it.

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On 1/10/2018 5:12 PM, Ed Huntress wrote:

Yeah, I meant follow rest. I was really more interested in information about the first two thirds of the post. Sometimes I feel like I have learned a little bit and others days I am utterly humbled. I could have used a steady and blended, but I modified the fingers on my steady to handle a larger piece of stock the other day and have not yet made replacement long fingers... and of course as you alluded to I'd have to move it around and blend the cuts.

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On 1/10/2018 5:05 PM, Bob La Londe wrote:








DOH!!!! It didn't finish like 416 because it wasn't 416. I was just getting ready to move the rod off the roller table in my cutting area when looked at a paper tag wrapped around the rod where it was clearly labeled 316L. Shit. On the other hand my metal vendor has agreed to take it back for a full refund even though I used over 3 feet of it. Well used is generous. I used one foot of it and destroyed two. LOL.
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