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Thread: Non-standard threads(?)

  1. #1
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    Default Non-standard threads(?)

    After I finished sorting through every type of fastener I had and labeled what they were, I ended up with a few unknowns. I ended up just tossing them out as I didn't know what to label them, but now I'm wondering why they didn't match any metric/sae standards. IIRC, it was very close to a #8 but a tad smaller. The TPI were also very close to ~40 but not quite. It was not a metric M4 thread either. It was actually a threaded coupler and several machine screws that fit nicely into the threaded coupler. They were also brass colored which also made then stand out. I don't think anyone made them as they did look like typical fasteners.

    Is it common for some fastener manufactures to create non-standard threads? It was so close to #8-40 but just a tiny bit smaller, and maybe ~41 or ~39 TPI, or maybe closer to M4x0.68 or maybe M4x0.72 or something strange.
    Last edited by 3 Phase Lightbulb; 01-14-2019 at 04:47 PM.
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  2. #2
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    Default

    4BA?
    5/32 ME?
    https://britishfasteners.com/threads/ME.html

    Or just botched production.. i have seen bolt eith grooves instead of helix and extension nuts that would only thhread half-way..

  3. #3
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    Default

    In short, Yes.


    In depth, there have been many standards for threads over the last hundred years or so. There are pipe threads, British, Japan, and even sewing machines have some! There have been millions of items made with threads that were proprietary to the manufacturer. If you think about it, there is no real incentive for a manufacturer to make a connector using a 10-32 thread if all of the other threads on the product are already being cut at 38 TPI for some odd reason. If the connector is only supposed to screw into their own machines, the thread does not matter as long as they mate.

    Dan
    At the end of the project, there is a profound difference between spare parts and extra parts.

  4. #4
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    Default

    Thanks guys, I figured it was just some non-standard thread. It probably came from a hardware lot that I got from my father that he probably got from Boeing surplus ~35 years ago in WA.
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  5. #5
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    The Brits have a number of odd-ball (to Americans, anyway) thread systems. BA, ME, BSC, etc. Some sizes are very close to imperial.

    Ed
    For just a little more, you can do it yourself!

  6. #6
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    What yyou've got sounds like a Holtzapfel Q thread, Major diameter 0.162" and 39.9TPI

  7. #7
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    Worth a fortune if you have one of these.

  8. #8
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    Default

    Quote Originally Posted by 3 Phase Lightbulb View Post
    After I finished sorting through every type of fastener I had and labeled what they were, I ended up with a few unknowns. I ended up just tossing them out as I didn't know what to label them, but now I'm wondering why they didn't match any metric/sae standards. IIRC, it was very close to a #8 but a tad smaller. The TPI were also very close to ~40 but not quite. It was not a metric M4 thread either. It was actually a threaded coupler and several machine screws that fit nicely into the threaded coupler. They were also brass colored which also made then stand out. I don't think anyone made them as they did look like typical fasteners.

    Is it common for some fastener manufactures to create non-standard threads? It was so close to #8-40 but just a tiny bit smaller, and maybe ~41 or ~39 TPI, or maybe closer to M4x0.68 or maybe M4x0.72 or something strange.
    You threw them out before you knew what they were for because you didn't know what to label them? How about "Oddball"...

  9. #9
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    I imagine that a fastener (screw) manufacturer will make any diameter and/or pitch that you want, if you pay for them. But I doubt that it is common.

    What I do know is that some manufacturers do deliberately make and use non standard screws in order to force you to purchase parts and accessories from them. Starrett, for one, is famous for this. I have a Starrett Planer and Shaper Gage, No. 995, that uses a small screw to attach the accessories. It looks like a standard #6 or #8 screw, but those will not fit. Nor would a #7 if you could find one or any metric size. It is a proprietary screw that Starrett created to force the users of this gauge to purchase the accessories from them. I talked to the factory engineers there and they admitted that it was completely non standard - a proprietary thread that only they use. Non standard diameter and I believe a non standard thread pitch too. I looked and could not find a die or tap for that screw. I had to buy the accessories from Starrett. No real choice. But they were happy to sell them to me ... at their prices.

    https://www.bing.com/search?q=Starre...t=10&FORM=PERE

    You may have had some Starrett proprietary screws. Or someone else's. Someone should develop a table of proprietary screw sizes. Or perhaps someone has.

    Other manufacturers have done the same. And I have seen far worse, far sneaker things that some manufacturers have done to insure that you do not buy from their competition.



    Quote Originally Posted by 3 Phase Lightbulb View Post
    After I finished sorting through every type of fastener I had and labeled what they were, I ended up with a few unknowns. I ended up just tossing them out as I didn't know what to label them, but now I'm wondering why they didn't match any metric/sae standards. IIRC, it was very close to a #8 but a tad smaller. The TPI were also very close to ~40 but not quite. It was not a metric M4 thread either. It was actually a threaded coupler and several machine screws that fit nicely into the threaded coupler. They were also brass colored which also made then stand out. I don't think anyone made them as they did look like typical fasteners.

    Is it common for some fastener manufactures to create non-standard threads? It was so close to #8-40 but just a tiny bit smaller, and maybe ~41 or ~39 TPI, or maybe closer to M4x0.68 or maybe M4x0.72 or something strange.
    Paul A.

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