knurl stainless steel

I see the how to drill stainless comes up every couple weeks. Here's a variation.
What's the trick to knurl stainless? I was looking at some dental tools
that have a beautiful job and are clearly quite hard. Some other stainless parts I've examined have botched up knurl jobs, but for adding friction for a grip, it's good enough.
I've knurled unhardened steels, brass and aluminum on the Sherline lathe. It's takes a couple passes some times, but there's enough fudge factor where the results are fine. I've not bothered to try stainless, but I suspect the multiple pass trick just isn't going to work at all, especially on a small machine.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Essentially, knurl it to full depth in two or three revolutions. (think SLOOOOW spindle speed) Otherwise, just like in drilling, it will work- harden, and not move anymore after that.
It helps - a lot - to use a clamping-style knurl. Side-pressure knurls often can't provide enough force to do it cleanly in that few revolutions; at least not without creating some undesirable forces on your cross-feed.
Lloyd
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 10 Nov 2015 17:48:32 +0000 (UTC), Cydrome Leader

Best to use a Cut type Knurling tool for the tough stuff
https://www.toolingsolutions.com/catalog/dorian_tool_Knurling-2012.pdf
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yeah... but most of the common SS alloys aren't "the tough stuff", they just require more care and knowledge of their properties than, say, aluminum.
Lloyd
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

    How about a cut style knurling tool. It may cost more than the lathe did, but it exists. :-)
    Enjoy,         DoN.
--
Remove oil spill source from e-mail
Email: < snipped-for-privacy@d-and-d.com> | (KV4PH) Voice (all times): (703) 938-4564
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Haven't been reading the rest of the posts, huh, Don? <G>
(And cut knurls aren't all that expensive...)
Lloyd
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 2015-11-11, Lloyd E. Sponenburgh <lloydspinsidemindspring.com> wrote:

    Well ... I did after I posted my thoughts. :-)

    Last I specifically looked for them in MSC, they were significantly over $1000.00 -- and my 12x24" lathe was about the same. Granted, the lathe was from 1957, and the cut style knurl was brand new. :-)
    O.K. Made by Dorian, $1,188.82 for one with a size range of 0.75" to 5" diameter workpiece. (Not counting the cutters, of course. :-) And -- a bit larger than my toolpost will handle. (3/4" shank, while I need a 5/8" shank max.)
    So -- this would not cut small enough to do the knurling on stainless steel dental picks as per the original question (which typically are hollow for ease of control).
    Yes -- I have used a scissors style knurling tool to knurl Stainless Steel -- but that was 416 SS -- a lot more workable than something like 304. :-)
    And for hollow handles for dental picks, I think that the crush force would be too great and destroy the workpiece. That is why I suggested cut style knurling tools.
    And yes -- you *can* get them for less on eBay -- but if you need them right *now* for a paid project, you have to deal with the new price. :-)
    Oh yes --- I also did not want to type too much, because I am recovering from the surgery which removed the titanium plate and screws from my arm -- which had been broken and repaired about a year ago. Remember that I was fairly quiet back then, too.
    Enjoy,         DoN.
--
Remove oil spill source from e-mail
Email: < snipped-for-privacy@d-and-d.com> | (KV4PH) Voice (all times): (703) 938-4564
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Glad you're recovering, DoN, and hope your life is a little less eventful for a while. How's the fire recovery coming?
Pete Keillor
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 12 Nov 2015 06:12:13 -0600, Pete Keillor

Could you insert a close fitting drill rod into the dental pick temporarily to prevent it from collapsing while it is being knurled?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thursday, November 12, 2015 at 8:17:13 AM UTC-5, snipped-for-privacy@nowhere.com wrote:

My gut thought is that if the rod is preventing the hollow dental pick from collapsing, then you will not be able to get the rod out.
Dan
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

The knurls only press two opposite sides in, they don't shrink the tube - they may even expand and lengthen it. Last week I pounded a home-made swage rod into a steel tube to straighten and expand it slightly, then pulled it out easily after hammering the OD a little.
-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

    [ ... ]

    [ ... ]

    Well ... the ones which I have seen are double-ended, with a taper down to each pick insert, and I suspect silver solder to join parts, but yes, you *could* support it that way, cut off a knurled section, and then silver solder the cones in place. (Or perhaps, if it all has to be stainless steel, TIG weld it with a machine to hold the parts and rotate.
    Some of the ones I have are small enough, and sold enough, so they could handle the crush, but the better ones are larger diameter and lighter wall thickness, so they are easier to control in the victim's mouth (mine). :-) So, it depends, I guess.
    Enjoy,         DoN.
--
Remove oil spill source from e-mail
Email: < snipped-for-privacy@d-and-d.com> | (KV4PH) Voice (all times): (703) 938-4564
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

    [ ... Original discussion snipped and "Subject: Header changed ... ]

    The arm is getting better -- but a lot of PT still to go through.
    The shop is usable by now -- with the Nichols mill, the Clausing 12x24" lathe, and the little Compact-5/CNC lathe working along with many other things.
    The Bridgeport, where the fire started, is being rebuilt. I got a BiJur oil pump to replace the dead one, and lots of expensive little plumbing bits, and have it all connected except the lube to the head and its ball screw. (Still taking that apart as my arm allows. It is spread out on the floor.
    But -- I was able to build a 10-meter J-pole antenna and get it installed before going back into surgery to recover the titanium parts. Interesting screws and plates. Looks like a Torx variant, though I haven't counted splines yet. (The overall length of the antenna is about 27', but all aluminum, so not too heavy. :-)
    Thanks,         DoN.
--
Remove oil spill source from e-mail
Email: < snipped-for-privacy@d-and-d.com> | (KV4PH) Voice (all times): (703) 938-4564
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

DoN, Why was the metal removed? Was it causing problems? I ask because I have LOTS of titanium and SS in both arms, my pelvis, and my back and none of these plates and screws have caused any problems. And all these metal bits have been in place for over a decade. Eric
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

    [ ... ]

    [ ... ]

    I hit a platform in the P.T. from the original surgery. In part because the therapist was restricted to avoid work in certain directions until the surgeon verified that the bone had regrown enough, and by the time he *could* attack the other motions, things had set up too much.
    In addition -- the top end of the plate was up close to the shoulder socket, and I think that it was hitting there limiting range of motion in at least one direction. Also, I was getting sort of "plucking" feelings in the tendons as I went through certain exercises, suggesting that the head or the point of at least one of the screws was near a moving part in my muscle system.
    Already, I cam move a good part of the way with less pain (though I will have to live on pain pills during the PT, which is supposed to be more aggressive this time).
    I was just barely able to reach up to the top of the drill press spider, and unbolting and lowering parts of the Bridgeport CNC mill head was a real trick. :-)
    I don't expect full range, but the ability to get the right arm up to assist with changing the battery in a ceiling mounted smoke detector (I need to change the batteries again, of course) would be a nice benefit. Last spring was a real pain (literal) changing the batteries. :-)
    I really should have done this break earlier, instead of waiting until I was 73 years old or so. Old farts heal *slowly*. :-)
    Enjoy,         DoN.
--
Remove oil spill source from e-mail
Email: < snipped-for-privacy@d-and-d.com> | (KV4PH) Voice (all times): (703) 938-4564
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

PT can do wonders. After my initial round of reconstructive surgeries, with pins sticking out of both arms and connected to the fixation system. I started PT. This was the morning after the crushing injuries. When I got home from the hospital I could hardly move my fingers. So I had to do exercises several times a day to free up my fingers. After the external fixators were removed I started more aggressive PT. Thought it hurt like hell during several months I was able to regain complete range of motion for all 10 digits. The PT was totally worth all the pain. Totally. Good luck with yours. Eric
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

    [ ... ]

^^^^^^^^     (make that "plateau". :-)
    [ ... ]

    Thanks! Yours is an impressive story, and gives me more hope for progress.
    Enjoy,         DoN.
--
Remove oil spill source from e-mail
Email: < snipped-for-privacy@d-and-d.com> | (KV4PH) Voice (all times): (703) 938-4564
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The picks I examined are solid and a touch over 1/4". I don't need to make new ones or anything like that, but am curious about the good quality work that went into them.
In production world, what sort of oil or coolant would be used? It's not really a cutting operation with conventional knurling wheels, but I suspect it's not an operation done dry either.

Did you get to keep your parts?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

    [ ... ]

    While it could be done with opposed knurls, I suspect that it was done with cut style knurls. They produce sharper diamonds and thus better non-slip grips.
    Of course, we don't know what alloys are used for dental tools. I would suspect something like 316 SS (Also used for making photo processing tanks back in the days of the Nikkor tanks.)

    I tend to use either Sul-Flo or Moly-Dee -- both good high-pressure lubricants for normal crush knurling. In particular, to keep the pins on which the knurls turn from being worn.
    But for a cut style knurler, a cutting lube would be preferred.
    [ ... ]

    Yep! One titanium plate, and an even dozen titanium self-threading screws (specialized for threading in bone. :-)
    It had to be cleaned and sterilized before I could receive the package.
    Enjoy,         DoN.
--
Remove oil spill source from e-mail
Email: < snipped-for-privacy@d-and-d.com> | (KV4PH) Voice (all times): (703) 938-4564
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Cool. Got GIFs?

Autoclaved?
--
The most powerful factors in the world are clear
ideas in the minds of energetic men of good will.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.