Cutting Threads Into Steel

Discussion in 'General Discussion' started by williamskg6, Jun 4, 2019.

  1. williamskg6
    williamskg6 Member

    I was wondering if anyone has been successful at cutting threads into the steel material. I need to have a couple of holes in my design threaded, and the thread pitch is too fine to 3D print (5/16-24 INF threads). I have a tool & die maker buddy of mine who is willing to try, but didn't want to go to the expense if it's not really possible.

  2. stonysmith
    stonysmith Well-Known Member Moderator
    It's possible, but I don't know how successful it will be. The Steel material has a consistency roughly equal to cast iron, and you might not get a smooth cut with the die.
  3. UniverseBecoming
    UniverseBecoming Well-Known Member
    I've tried it and it's highly annoying. The stainless powder is hardened and the bronze is soft and the two in conjunction tend to make things very tough. I was doing something like 10-24 so I couldn't apply a lot of torque and I didn't try cobalt or carbide taps. At 5/16th you can apply a LOT MORE torque so maybe it wouldn't be an issue but be ready to deal with some extremely tough material.

    Speaking of cast iron, it is brittle like cast iron too and will crack if tweaked too much.

    If I had to do it again at that thread size I would design for threaded inserts.
  4. ishtob
    ishtob Member
    I have had good experience tapping the steel prints long as it is not a blind hole or a deep thread (<1/4inch has been easy with a 8-32 tap by hand) i've broken 2 taps doing holes that were longer than 1/4inch but prob because I didnt apply enough cutting fluids. Expect a lot of resistance and the tap dulls pretty probably due to the steel particles. Go slow, and backup out/clear the dust often