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cdspk1-Visitor
1-Visitor
September 21, 2010
Question

Units

  • September 21, 2010
  • 34 replies
  • 5619 views

I'm used to seeing feet, inches and pounds usedin this forum but had kind of assumed it was a legacy thing, I was quite surprised to learn that (as one of the last three countries with Burma and Liberia) the US still has imperial units as its official measurement system.

From a professional point of view it would be useful to know whether US college engineering students are taughtat all inSI units aswe're starting to see a lot more US graduates here in the UK,

Cheers, Sean

    34 replies

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    M
    MikeCavins14-Alexandrite
    14-Alexandrite
    September 21, 2010
    My recollection is that there was an issue with the cost of converting
    every single road sign (among other things) in the US from miles to
    kilometers.

    It's not a big deal for Rhode Island, but California had big huge
    problem with it.


    Mike


    Mike Cavins
    Design Engineer
    CSC Worldwide
    (614) 527-5767

    >>> "Reifsnyder, Robert" <-> 9/21/2010 9:57 AM
    >>>

    God, I hope we never use SI for general purpose. I’m fully conversant
    with SI and can and will use it when needed, but I hate the idea that
    they tried to force this on us beginning in the 70’s as someone else
    pointed out. Even with all the pressure we simply won’t use SI and the
    time has come for us to stop pushing it. I have no problem teaching it
    alongside the Imperial units (English units here) just as we should
    learn any other languages we can. We have wasted far too much effort and
    money trying to force this. If and when people decide that they are
    comfortable with it, it will change. I’ve always found it interesting
    that even the rest of the world has maintained certain things in inches,
    namely wheel sizes on cars. They are still in 14,15,16 inch and so on.
    In the early 80’s Ford and Michelin tried coming out with 360mm and 395
    mm wheels and tires for some of their cars. It couldn’t catch on not
    just here but everywhere. I’m not for forcing anyone else to change to
    English units please don’t try to force us to change ours. It’s another
    language, that’s all. We need to be conversant in both.


    Rob Reifsnyder
    Mechanical Design Engineer/ Pro/E Librarian
    L
    Mission Systems & Sensors (MS2)
    497 Electronics Parkway
    Liverpool, NY 13088
    EP5-Quad2, Cube 281
    B
    BobSchwerdlin1-Visitor
    1-Visitor
    September 21, 2010
    Yes, I believe they had catastrophic results because some orbital calculations were done in Imperial units and some were done in SI, only to have mission failure. BUMMER !

    Bob
    T
    TimMcLellan12-Amethyst
    12-Amethyst
    September 21, 2010
    I don't want to sway too far off the original question - Most students are
    taught both and I use both every day.



    Rob has a good analogy. Now the next big question, which one is more
    efficient and effective for your business?



    I find that a majority of my clients use SI (e.g. Consumer Electronics,
    Automotive, Consumer products, etc) while some (e.g. Defense) primarily use
    Imperial (English) units. I believe that this is due to business aspects
    (Assembly and Manufacturing is primarily in the U.S.). Do what is right
    and valuable for your business.



    A quick search came up with this (Very pro SI - but interesting comments):

    P
    ptc-1571021-Visitor
    1-Visitor
    September 21, 2010


    All,



    Way back in the 60's, most of my courses used metric measures (though you
    were not so concerned with hardware types}. Some companies put inch inside
    the box and metric on the outside (!?).



    Most of the military is in SI. Many multinational companies with products
    that are export require that the interface hardware be metric. Finding
    American screws in most countries is harder than finding metric screws here.




    One company was changing from inch/fractional to inch/decimal and sure
    enough 10 inches= 1 foot! To mitigate the errors, we got into the habit of
    designing with decimal fractions, .312 not .30 or .35.



    Bill







    M
    mheath1-Visitor
    1-Visitor
    September 21, 2010
    If you look in the Machinery's Handbook it states " In 1866 the United States, by act of Congress, passed a law making legal the meter, the only measure of length that has been legalized by the United States Government." .
    P
    pfariello1-Visitor
    1-Visitor
    September 21, 2010
    Wow, I had to scroll way back in my inbox to see where this all started.

    Thinking back, my engineering classes were taught in both units, graduated in 95.

    Patrick Fariello
    B
    bbenitez1-Visitor
    1-Visitor
    September 21, 2010
    I've been a Designer for almost 35 years

    The BEST three years of my career were the three spent using JIS Metric
    Units.



    .34375, .6875, .90625 - how does one explain to an engineering student the
    value of using these fractions?



    Anthony R. Benitez

    Senior Mechanical Designer

    Drafting Supervisor

    Applied Research Laboratories

    The University of Texas at Austin

    K
    kdemont1-Visitor
    1-Visitor
    September 21, 2010
    I didn't realize that the government thought they could legislate thought that
    far back in our history.


    J
    joepaul881-Visitor
    1-Visitor
    September 21, 2010
    Well, knowledge on this exploder isn’t limited to Pro/E anymore I guess. Made me curious, found this site and lo and behold, it is listed at the end.

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