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wood thread on a 1/4" steel rod

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  • wood thread on a 1/4" steel rod

    I would like to produce a wood thread(so I can screw rod into wood) on a 1/4" mild steel rod. I would like the threaded portion to be 3/4" in length. Before I weld a portion of a wood screw on the rod does anyone have an idea how this could be accomplished with lathe and mill capabilities? Thanks Paul

  • #2
    i don't know the specs for a wood thread, but 1/4"?? seems likely the wood would tear out, unless its lignum vitae or something (but then you could tap it NC). Why not drill out the wood and epoxy in a tapped insert?
    in Toronto Ontario - where are you?


    • #3
      Buy 'em

      You can buy items just like or for this - wide range actually - at the larger/better hard-ware stores.

      Not expensive at all - and really do the job.

      Well, at least you can in OZ.

      I'd expect that anyone with a "wood-working/furniture" interest or back-ground could/will help with this one.


      • #4
        If the rod is already 1/4", I'm not sure how much holding power you'd get once you remove enough to get good threads for wood. My assumption is that this isn't structural. I would be concerned that small amounts of force could cause splitting if you have a respectable length of rod protruding from the wood. I would look at bolting through if any forces would be expected.

        Grind a very wide profile threading tool and use the longest feed your lathe can handle? Something like a 4 TPI feed with a 3/16" flat between 70-80 degree shoulders?

        More of a smithing method than anything else, but you could find a template screw and make dies then use the dies to finish the end of the rod.

        Put a shoulder on the end of the rod and turn something like a #6, #8, or #10 thread to match a threaded insert as suggested in the previous post?

        Hanger bolts might fit your bill if you could find them in the right size.

        $0.02, and exhale...


        • #5
          Its the holiday season and some of these guys are still to full to think very well.

          A quarter inch lag screw is plenty structural.
          A quarter inch lag screw is about 10 tpi. with a truncated nose on a threading tool.
          This can be equavalent to a quarter twenty, two start thread with one thread cleaned out at root diameter.

          You can go to a 40 or 30 degree V to achieve the fin like threads if you want.

          Any wood screw of any size has trouble going in unless you do a tap-drill first.

          the only difficulty is doing a type A point. (which you don't need if you do a tap-drill first)

          I would have the root dia extend out from the first thread
          (higbee style) to act as a starting pilot.

          Hth Ag


          • #6
            Hanger bolts.

            I think that - as advised by 2ManyHobbies - if you want a "metal screw" on the other end you might like to consider hanger-bolts:






            • #7
              If by a "wood thread" you mean a square thread as seen on things like wooden nutcrackers, old winepresses, etc, 1/4" is a bit small for that, but not impossible, I guess.

              I rarely see any such smaller than about 5/8" diameter.

              The lag screw is a fundamentally different item, not comparable to the "wood thread" as above. But it might well be a better solution, if it can be used. That or an insert.

              The "wood thread" has actually cut the wood fibers, and relies on the cross-grain shearing strength of a relatively smaller area of wood. The lag screw may cut some fibers, but it distorts others, compacting the wood and retaining more strength, and also has almost double the shearing area of wood, since the threads don't take up much room in the wood.

              The insert is as strong as the glue allows,, up to the wood's inherent strength.
              Last edited by J Tiers; 12-31-2007, 01:03 AM.
              3751 6193 2700 3517

              Keep eye on ball.
              Hashim Khan

              If you look closely at a digital signal, you find out it is really analog......


              • #8
                Don't know your exact application but these work great for the threading bolts to wood. They are called t-nuts. They are available at all hardware stores. Don't know if you are familiar with them or not or if there is a specific reason to put such a serious thread on a metal shaft such as common wood threads.

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                • #9
                  they have the hanger bolts at the big boxes stores in the fancy bolt boxes. Ect they come in all size dia and lengths. I use a number of them in the parrot perches. They also come in one version that is back to back word screw to. For wood to wood joining. they also come in assorted dia at the big boxes.
                  Been there, probably broke it, doing that!
                  I am not a lawyer, and never played one on TV!
                  All the usual and standard disclaimers apply. Do not try this at home, use only as directed, No warranties express or implied, for the intended use or the suggested uses, Wear safety glasses, closed course, professionals only


                  • #10
                    Thanks for all the good ideas and suggestions. Paul


                    • #11
                      yep i was going to suggest what YOD did...

                      whats this for anyway? (if you dont mind me prying that is...)