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#10 screw and 3/16 screw

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  • #16
    Metric is for weenies.

    Real men use the Imperial system of weights and measures, hunt bear with a switch, and floss their teeth with barbed wire.

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    • #17
      Originally posted by John Stevenson
      Ok take the imperial equivalent of 12mm as being 1/2"

      In 1/2" and I have just checked my tap list you have 12 tpi, 13, 16, 18, 20, 24, 26, 30, 32 and 40

      Now ask for a 12mm bolt and 90 % of the time you will be given a 1.75 pitch bolt, the other being specials.

      Out of the 10 threads I have listed for the 1/2" which one is standard ?

      .
      the standard NC thread is 1/2-13 The standard NF thread is 1/2-20

      All the rest are specials for particular purposes, although one may be an "NEF" or national extra fine" .... i.e. basically a special.

      You can MAKE a 2"-36 thread....... doesn't make it a hardware store standard.. it isn;t the US threads in question,.... we know they have oddities from the last 150 years + of industrial activity.

      It's the holy standard METRIC, which claims to be so standard, but turns out to be just as messed up as any other system in reality.
      1601

      Keep eye on ball.
      Hashim Khan

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      • #18
        Originally posted by J Tiers
        the standard NC thread is 1/2-13 The standard NF thread is 1/2-20
        So two standards ?
        Send the lad out to the hardware shop for a standard 1/2" bolt, what will he come back with ?

        Outside of the US no one uses UNF / UNC any more. At one time the Auto industry in the UK used these as a lot of companies were American based but with recent sell off's Japan and Europe have taken over as owners and they use metric.

        It's the holy standard METRIC, which claims to be so standard, but turns out to be just as messed up as any other system in reality.
        Send the lad out for a M12 bolt and he'll come back with a M12 x 1.75 bolt.

        .

        If he wants any other pitch he'll have to ask for it.
        .

        Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.



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        • #19
          Originally posted by John Stevenson
          So two standards ?
          Send the lad out to the hardware shop for a standard 1/2" bolt, what will he come back with ?

          Outside of the US no one uses UNF / UNC any more. At one time the Auto industry in the UK used these as a lot of companies were American based but with recent sell off's Japan and Europe have taken over as owners and they use metric.



          Send the lad out for a M12 bolt and he'll come back with a M12 x 1.75 bolt.

          .

          If he wants any other pitch he'll have to ask for it.



          when you go to the hardware store, anybody worth a damn will know to ask you "coarse or fine thread pitch?" when you ask for that 1/2" bolt...
          -paul

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          • #20
            Just to add a bit of interest to our lives...the tapped holes in those aluminum 19" server/relay/telecom racks full of high tech equipment are usually#12-24.

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            • #21
              So two standards ?
              No. One standard with fine and course pitch. Metric has fine and course as well. Metric and imperial both also offer "special" threads but that's just stupid in most cases and we won't go there. No advantage of one over the other. The problem is that switching to metric takes tons of cash for tooling, so demanding that the manufacturing behemoth the US once was to change to metric because some French wussy, bottle-glasses Beaker scientist could then just move the decimal instead of having to remember a conversion factor just wasn't going to happen.


              Send the lad out for a M12 bolt and he'll come back with a M12 x 1.75 bolt.
              Yea and over here he'll bring you a 1/2-13. If you want fine pitch, then you'll have to send him back a second time.

              I don't see why anyone thinks there's such an advantage to metric. The metric bolt notation even looks clumsy to me. Ever screw up and read 1.25 to be 1.75 for a pitch and vise-versa? That's the problem with metric. You want to be lazy and just move a decimal place? Fine. Now you have decimals in everything because you aren't allowed to just divide something up anymore. Especially if it's thirds or something. Oh God - Blasphemy! 1/3rd of a centimeter? Unheard of! Why? (I think the American engineers picked 13 for the pitch of a 1/2" bolt just as a jab to the metric fans. "1/13 of an inch? Is that even allowed?" hehe.)
              I think people who love metric are the same type who hate fractions or something. US units are good for learning fractions. Units are supposed to be something divided up to begin with right? Whomever limited the divisions to only 10 was just short-sighted. Why not be able to divide something into whatever unit is the most useful instead of arbitrarily picking 10? THAT'S right - I called metric "arbitrary" and I meant it.

              If a guy is not good with numbers, he's not going to be much good in either system. He'll be able to blame the "other" system though, so he's got that going for him.

              The world will NEVER settle on a single standard I don't think. Unless metric could include the two most universal units in the universe, it will never take off. I'm speaking, of course, about the units of HH and FF. These are used more than any other unit in history and their intuitive relationship to all things is apparently undeniable. It's the newscasters' standard measure and the abbreviations of course stand for Human Hair and Football Field.

              This silly "metric system" thing doesn't stand a chance.
              Last edited by tyrone shewlaces; 01-11-2010, 05:56 PM.

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              • #22
                Originally posted by websterz
                They're still pissed that they got beat by a bunch of colonial hicks.
                NO Were pissed you needed the help of the French

                Steve Larner

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                • #23
                  Did anyone mention that 3/16-24 is a very close 10-24 thread? Same thing pretty much except for the major diameter for the 10-24 on an OD thread is .1890 for the high limit class 2, Machinery's handbook ed. 24. The only real change being about .0025 on the OD thread allowance, the 3/16 being a bit smaller by that much for the high limit.. Found a 3/16-24 in a very old machinist textbook in my library finally. I would wonder about the loseness, the 10-24 tap may be an H3 type? The H shows your "oversize" cut allowance.
                  CCBW, MAH

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                  • #24
                    I think it just boils down to what you were brought up using. I have used imperial since I was a kid so my mind naturally works in imperial units MUCH easier. I can instantly envision a 1/2-13tpi bolt in my head like a picture. But if I try and envision a 12mm 1.75 pitch I have trouble.
                    Given a lathe that cuts all threads, I always will select a imperial thread for my projects just because I get all warm and fuzzy and stay in my comfort zone.

                    Any real Hardware store in the U.S. has a decent bolt section with coarse and fine selections for imperial. Most will have a good selection of metric fasteners as well.
                    Again, If I am cobbling up something and need fasteners for the project I always choose imperial. It has nothing to do with which is better, just sticking with what I know best.

                    Old dog, old tricks right?

                    Steve

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                    • #25
                      Originally posted by tyrone shewlaces
                      The problem is that switching to metric takes tons of cash for tooling, so demanding that the manufacturing behemoth the US once was to change to metric because some French wussy, bottle-glasses Beaker scientist could then just move the decimal instead of having to remember a conversion factor just wasn't going to happen.

                      .

                      That sums it up "the manufacturing behemoth the US once was"

                      You have no control over imports.

                      Why not insist that all Grizzly machines ship in with UN threads ?

                      Will the new South Bend have UN series threads?

                      BTW I'm not saying that one system is better than another all I'm saying is that you need to look around and see what others are doing.
                      Who else uses the number thread system for threads below 1/4" in the world ?

                      You are buying in imports designed in metric but who wants to buy imperial exports in todays multi national world ?

                      Look at this.

                      http://www.ctctools.biz/servlet/the-.../82/Categories

                      There has been enough demand for them to now make R8 tapers with M12 drawbar threads instead of 7/16" UNF because many countries don't have a clue what UNF is.

                      .
                      .

                      Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.



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                      • #26
                        Originally posted by John Stevenson
                        There has been enough demand for them to now make R8 tapers with M12 drawbar threads instead of 7/16" UNF because many countries don't have a clue what UNF is.
                        No big deal, NMTB taper tooling has been available with Imperial and Metric threads for years. It is a matter of use.

                        I will make a WAG that 9 out of 10 consumers in any country neither know or care what threads a given piece of equipment uses. It is only a very few, such as ourselves, who even know what the various threads are. To most, they are big or small or maybe medium sized.

                        A 9/16" bolt uses a 9/16" wrench right?
                        Jim H.

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                        • #27
                          Originally posted by JCHannum

                          A 9/16" bolt uses a 9/16" wrench right?
                          It does if it's Whitworth

                          Tim

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                          • #28
                            Ssshhh Tim,
                            Don't let on that old Joseph who set the first standards up before American was even found and used 55 degrees with rounded roots and flanks is still the strongest thread form to date.

                            .
                            .

                            Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.



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                            • #29
                              Really , we just don't care.

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                              • #30
                                Originally posted by Uncle O
                                Really , we just don't care.
                                Of course you do, otherwise you wouldn't have posted that.

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