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Thread: How is this ok?

  1. #1
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    Default How is this ok?

    Is there some logic at work I don’t understand?

    It’s a 1/2 inch lag bolt that measures 0.335”.

    That throws off, well, everything.

    Surely I’m missing something.

    Edit-I guess it’s the thread diameter that is normally stated. Still short. But the shank diameter seems so far off.

    E14CEC0A-47BA-41CB-A338-D932430D8FE0.jpg


    40D342E4-93C3-41BC-96BF-90D7B8520168.jpg
    Last edited by bluedog225; 03-01-2021 at 10:57 PM.

  2. #2
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    Default Re: How is this ok?

    “Nominal” dimensions. Same as a 2x4 measuring 1-1/2” x 3-1/2”.

    Those SPAX hardware lags aren’t same steel as traditional lags either so they can get away with less metal & still meet specs a 1/2” conventional grade 2 lag does.

  3. #3
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    Default Re: How is this ok?

    But why would you buy a grade 5 half inch fastener to meet grade 2 specs?

  4. #4
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    Default Re: How is this ok?

    Quote Originally Posted by bluedog225 View Post
    But why would you buy a grade 5 half inch fastener to meet grade 2 specs?
    dis why

    SPAX PowerLags are ICC-ES and DrJ code-compliant for deck ledger attachment multi-ply applications and do not require pre-drilling for full strength ratings, offering dramatically increased installation speed across your projects.

  5. #5
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    Default Re: How is this ok?

    I think you are right. It’s implied that “full strength” is grade 2. I can’t find it expressly stated that you are buying a grade 5 equivalent of a grade 2 bolt because it is easier to install. I love the GRK and Spax fasteners. But this seems shady as heck.

    If I were buying a 1/2 hex head lag bolt, I would expect to get something like this:

    B8E12378-81C0-4C5B-9D34-243EEC5A7196.jpg

  6. #6
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    Default Re: How is this ok?

    I use these rather than conventional lags strictly for their appearance.

    Similar engineering to those SPAX fasteners but with a truss head shape and a six-lobed Torx drive socket I’ve become a fan of.

    A few times I’ve managed to twist the heads off conventional hex-head lags, have yet to do that to a Torx-drive head type.
    Last edited by sp_clark; 03-02-2021 at 08:44 AM.

  7. #7
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    Default Re: How is this ok?

    Spax wearing Spanx ?

  8. #8
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    Default Re: How is this ok?

    Thanks. Comparing the Hillman to the Spax.

    At the stated 5/16, the Hillman major diameter is 0.305-0.315.

    5/16 is 0.3125 (actual)

    The 5/16 Spax major diameter is only 0.217.

    Though the Hillman doesn’t state a grade. It does list the tensile strength. I haven’t done the math to figure out the grade.

    For the normally intended use, something like deck building, I suspect they are all fine.

    Interesting stuff. I enjoy digging around in this type thing.

    I keep ending up back at the old fashioned hot dipped hex head lag.

  9. #9
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    Default Re: How is this ok?

    Quote Originally Posted by bluedog225 View Post
    Thanks. Comparing the Hillman to the Spax.

    Interesting stuff. I enjoy digging around in this type thing.
    As do I. Metric stuff's even more interesting....

    Quote Originally Posted by bluedog225 View Post
    I keep ending up back at the old fashioned hot dipped hex head lag.
    For the OP's intended use, I'm with you on that. Appearance doesn't count as much as longevity and strength. Good enough is good enough for his purpose.

  10. #10
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    Default Re: How is this ok?

    I can understand your concern. If you want a half inch bolt, then that's what you want.
    My impression is that the manufacturer of the Spax bolt is claiming equal or superior performance to the one you wanted, along with avoiding the need to pre drill a hole. It is hard to determine whether that these claims have been proven by an engineer, or are just designed to make a sale. In America's litigious society, the latter would seem to be a risky path to take.
    There is nothing quite as permanent as a good temporary repair.

  11. #11
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    Default Re: How is this ok?

    The performance may be the same in tension, but will not take the same shear load as there is less bearing area in the wood.
    It really is quite difficult to build an ugly wooden boat.

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  12. #12
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    Default Re: How is this ok?

    In my opinion, this is a more accurate, defensible approach.

    86F9F3FA-8579-4989-8566-338E90DD03FF.jpg

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