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I'm working some steel rods into small studs, the problem is that when I tighten them in my vice, they get severely bitten by the vice's jaw blocks, leaving some nasty marks in the rods. I can live with the marks, but some rods have very small flat shanks and the marks interfere with the next threading session. I'm not new in metal work and know about adding protection sheets to the jaw (aluminum, copper, etc) to avoid having the work being bitten, but I can't tighten the vice enough: I get the rod slipping, specially because the threading lubrication.

So far I tried protecting the rods: aluminum, thin sheet metal, copper, rag, paper, cardboard...sandpaper (which kinda works), but still get the rod slipping at some point.

Any suggestions/ideas/experience in how to secure the rods fair enough to thread them without the vice bite the shanks?

  • Have you tried rubber pads for the vise? – Ben Feb 23 '17 at 0:34
  • The only thing among a dozen I tried which I didn't think off :) How thick do you suggest? With a notch where the rod should be placed? – Aram Alvarez Feb 23 '17 at 0:43
  • Maybe around 3/8" You can probably get away with thinner. Some like amazon.com/dp/B0057PUEZO/ref=psdc_5739459011_t1_B000LIOUM0 come with some notches in them. Actually that one is plastic/polyurethane but same difference. – Ben Feb 23 '17 at 0:45
  • You say you are threading rods ... are these threaded rods? I mean, is the entire thing threaded? I'm not quite understanding what your stock is here. – Pᴀᴜʟsᴛᴇʀ2 Feb 23 '17 at 1:54
  • @Paulster2: I'm making regular stubs, threads in both extremes, no thread in the middle of the shank, not totally threaded. So I'm using calibrated rods (M8 and M10) made of some kind of semi-hardened steel :) more hard than a mild steel, yet "threadable" by hand. The problem is: when placing the rod in the vice, it bites it, so first thread works ok, but turning the rod upside down to make the other thread, I could reach some damaged areas – Aram Alvarez Feb 23 '17 at 2:48
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Use a collet block

Collet Block

These are designed to take a collet and tighten down on a rod. It works just like collets in a lathe or the spindle on a mill. You can hold the block in a vise, install the appropriate collet, tighten it down, then get to work without damaging the stock material.

EDIT: Alternatively, use V blocks. These are less preferred because they can still damage your rod, and they only provide four point contacts instead of continuous circumferential contact, but they're also less expensive.

V Block

2

Have some spare length, create the first thread, then use a couple of nuts to "lock" on to the thread, cut off the damaged spare then do the second thread on a virgin section. A lot cheaper than purchasing collets etc. No disrespect to toolmakers and the precision they work to!

  • That's a pretty good idea, but it can be hard to get jam nuts aligned exactly for use in a vise. He also risks pivoting in the plane of the vise jaws, but that would have been a problem anyway. It all depends on how he's cutting the threads. – Hari Ganti Feb 23 '17 at 20:23
  • All valid points, but a possibility is to clamp on only one of the two nuts - those "double-length" nuts are especially good... – Solar Mike Feb 24 '17 at 7:07
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sounds mad but a block hard wood drilled and split should do it, may be a sharper cutting tool with lot of reverse action as you fight it. goodluck.

  • Your answer is unclear. I can't visualise the solution you are proposing. Can you please clarify? – Chenmunka Feb 24 '17 at 18:34
  • I think he means making something like this: paragonmachineworks.com/PDGImages/FT4022.jpg I used to use them to work on bike tubes where they had a larger OD, but a very thin wall, so they were prone to crushing. Not sure about that last bit though... – Hari Ganti Feb 24 '17 at 19:17

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