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Screw Threads

This topic contains 32 replies, has 15 voices, and was last updated by  CB 1 week, 6 days ago.

Viewing 13 posts - 21 through 33 (of 33 total)
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  • #661933

    smallerstick
    Pro
    Listowel, ON

    I would try both metric thread pitch size screws there is a m4/.07 and a m4/.05. You will most likely have to find a true fastener supply house. The fine thread m4/.05 is probably the harder to find. Both are only 0.1656mm smaller than a #8 coarse/fine thread screw.

    This problem could be avoided completely if the US would just adapt to metric system and stop using Standard nuts,bolts,screws,wrenches,lbs,inches,etc.
    once you learn the metric system it is so much easier. And you would only need one set of tools. Not a standard set and a Metric set.

    It would make life so much easier if there was only one set of measurements considered “standard”. Agreed, the metric system makes so much sense. Science, medicine, industry worldwide uses the metric system. US (and some Canadian) domestic use is the only holdout.

    Liberia and Myanmar still use the imperial system along with the USA.

    LMAO Well, with economic powerhouses like that still onboard, I can see the US holding out, although, I did see a reference to Myanmar offering to switch in 2013.

    Duct tape can't fix stupid, but it muffles the sound.

    #661977

    GTokley
    Pro
    Madoc, ON

    I only use metric at work and I always use imperial at home.

    Greg

    Work Smarter Not Harder

    #662037

    theamcguy
    Pro
    Fayetteville, NC

    I only use metric at work and I always use imperial at home.

    About the same here. I only buy metric if I need to replace. If I am buying new fasteners it is always SAE/Imperial.

    Automotive Pro
    Fayetteville, NC

    #662079

    GTokley
    Pro
    Madoc, ON

    I only use metric at work and I always use imperial at home.

    About the same here. I only buy metric if I need to replace. If I am buying new fasteners it is always SAE/Imperial.

    I pretty sure my hardware doesn’t carry that many metric sizes.

    Greg

    Work Smarter Not Harder

    #662093

    smallerstick
    Pro
    Listowel, ON

    I only use metric at work and I always use imperial at home.

    About the same here. I only buy metric if I need to replace. If I am buying new fasteners it is always SAE/Imperial.

    Funny, I do the opposite; I only use SAE to replace. Any new applications will get metric wherever possible.

    The only exception to that is 1/4-20 fasteners for jigs and fixtures.

    Duct tape can't fix stupid, but it muffles the sound.

    #662113

    xtsallad
    Pro
    Dallas, TX

    I only use metric at work and I always use imperial at home.

    About the same here. I only buy metric if I need to replace. If I am buying new fasteners it is always SAE/Imperial.

    Funny, I do the opposite; I only use SAE to replace. Any new applications will get metric wherever possible.

    The only exception to that is 1/4-20 fasteners for jigs and fixtures.

    That’s pretty much what I do as well. Replace sae with sae if I have to match and new gets metric whether at work or home. Work sees more metric. I also can’t wait for Phillips drive to go away with metric. it’s ok for really low torque applications but designed to cam out and I don’t like that.

    j

    #662143

    whitehill
    Pro
    Ottawa, ON

    There have been three or four different sizes/threads of screws included with the light fixtures on my current reno. I need to remember to check that they fit the box before getting up there with the fixture in one hand! I’m not sure why there is so much variety. Oh, and some with messed up threads too. Quality of included hardware seems pretty bad nowadays.

    #662167

    theamcguy
    Pro
    Fayetteville, NC

    Quality of included hardware seems pretty bad nowadays.

    That’s because it is cheap off shore made. The quality of the included fasteners leaves a lot to be desired.

    Automotive Pro
    Fayetteville, NC

    #662195

    smallerstick
    Pro
    Listowel, ON

    Quality of included hardware seems pretty bad nowadays.

    I’ve noticed the same thing. Some fasteners you have to fight to get in and others fall out, literally! At the retail price of lighting, I don’t see the reasoning.

    Duct tape can't fix stupid, but it muffles the sound.

    #662271

    GTokley
    Pro
    Madoc, ON

    Quality of included hardware seems pretty bad nowadays.

    I’ve noticed the same thing. Some fasteners you have to fight to get in and others fall out, literally! At the retail price of lighting, I don’t see the reasoning.

    Yes I have experience this also. Is very frustrating the price you have to pay for stuff.

    Greg

    Work Smarter Not Harder

    #662279

    jponto07
    Moderator
    Bloomington, IN

    I would try both metric thread pitch size screws there is a m4/.07 and a m4/.05. You will most likely have to find a true fastener supply house. The fine thread m4/.05 is probably the harder to find. Both are only 0.1656mm smaller than a #8 coarse/fine thread screw.

    This problem could be avoided completely if the US would just adapt to metric system and stop using Standard nuts,bolts,screws,wrenches,lbs,inches,etc.
    once you learn the metric system it is so much easier. And you would only need one set of tools. Not a standard set and a Metric set.

    It would make life so much easier if there was only one set of measurements considered “standard”. Agreed, the metric system makes so much sense. Science, medicine, industry worldwide uses the metric system. US (and some Canadian) domestic use is the only holdout.

    But what would all of us over-brained Americans do if we didn’t have to figure out all those fractions 😉 ?

    I don’t have an issue with the imperial system myself as I’ve been using it my whole life…but I completely sympathize with those who have to learn it later in life.

    Jon P.
    Timber Carpentry & Construction
    https://www.facebook.com/timbercarpentry/
    Instagram

    #685046

    Boschmanbrian
    Pro
    Montreal , QC, Canada

    Oh man, I personally prefer the standard system, but dealing with airbus dwgs or even particular militarily drawings, I can definitely see the difference in very precise measurements,
    But as far as construction, not much of a difference for me

    #685098

    CB
    Pro

    Metric M4-0.5 That’s 36 TPI…
    Metric M4-0.7 is 32 TPI…

    Negative.

    Metric fasteners are expressed in measurement per thread, and English Imperial/SAE fasteners are expressed in threads per measurement.

    Obviously, with metric fasteners, the measurement is millimeters, and with Imperial fasteners, the measurement is inches. Hence, a metric fastener thread pitch is expressed as millimeters per thread, whereas an SAE fastener thread pitch is expressed as threads per inch.

    Therefore, it is mathematically impossible for an M4-0.5 to equate to “36 TPI”, because we already know that one inch is equal to 25.4 millimeters, and the 25.4 millimeters contained within an inch divided by the specification of .5 mm per thread would yield 50.8.

    As such the threads per inch equivalent of an M4-0.5 metric fastener that has a half millimeter spacing between thread crowns would be 50.8 TPI. Not 36 TPI.

    However, using the same simple math, the M4-0.7 does so happen to work out to something close to, but not quite 36 TPI, but definitely not the “32 TPI” as quoted above. Walking it through to find TPI, we divide the metric equivalent of one inch, which is 25.4mm, by the metric thread pitch of .7 millimeters per thread, which turns out to be 36.285714 TPI. Somewhat of a fit to 36, but still not quite right.

    I think iponto07 nailed the issue right away in post 647871 upthread. The more likely difference was 8-32 vs 8-36, not metric. The original post only said that #8 machine screws were obtained, without identifying which thread pitch, and the lack of identification of thread pitch for the #8 screw suggests that thread pitch was the most probable issue, without having anything to do with metric.

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