Do you use THOU?

Discussion in 'General Science' started by debjit625, Sep 19, 2011.

  1. debjit625

    Thread Starter Well-Known Member

    Apr 17, 2010
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    What you use for 1/1000 of an inch, thou or mil ?
    I use mil and so do others around me but I came upto this term and I am confused if anybody use this term or not....:confused:

    I have heard in PCB industry this term is used, any way in my CAD or the manufactures use both imperial and metric i.e.. inch,mm,mil,micron.

    For those who don't know what I am talking about : http://en.wikipedia.org/wiki/Thou_(length)

    Thanks for your replies :)
     
    Last edited by a moderator: Sep 19, 2011
  2. Wendy

    Moderator

    Mar 24, 2008
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    I use mils. The gold wire I use is 1 mil, for example. I suspect it is a regional thing. 1 mil = 1/1000"
     
  3. BillO

    Well-Known Member

    Nov 24, 2008
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    Hmmm,

    I have always used thou for thickness or gaps, but used mil for the diameter of small holes....and I don't know why.
     
  4. someonesdad

    Senior Member

    Jul 7, 2009
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    Both terms are in common use. "thou" is probably more common colloquially in the machine shops in industry I used to visit when I had a project being made there. For example, read Guy Lautard's "Machinist's Bedside Reader" books and you'll find it used a lot. Besides meaning thousandth of an inch, "mil" pops up in things like circular mil and angular measure where it means milliradian. However, in the industries I worked in at least, you'd never see it on drawings -- all dimensioned stuff was either in inches or mm.

    Since my machinist tools are all calibrated in inches and I've been an amateur machinist for 50 years, I think in thous when I'm working in the shop and, when doing careful work on the lathe or mill, in tenths, which is a tenth of a thou.

    One place where mil was commonly used was in the plating shop to measure the thickness of a plated film. At least in one industry I used to work in, this was quickly taken over by the micron. Since my industrial background is in thin films, the common unit for thin film work 20-40 years ago was the Angstrom. Fortunately, we're starting to see more SI measurements these days in SI units like nm, um, and pm. Frankly, I'd like to take the whole non-SI morass and dump it off the end of a pier... :p
     
  5. atferrari

    AAC Fanatic!

    Jan 6, 2004
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    Seen it used only by PCB development software. Cannot recall which one.
     
    Last edited: Sep 19, 2011
  6. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    Personally I distrust using "mil" as it sounds more like 10^6 and not 10^-3. So when I can I use .001 inch.

    That said, many programs and vendors prefer mil as 10^-3. So I use it where I must, but I don't like it.
     
  7. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    Agreed. And "mil" is a poor choice of term as many metric countries use "mil" as a common abbreviation of millimeter, and the confusion compounded by the fact that both terms are small units of measurement!

    And, even in Imperial countries, why would you need two terms for the one unit? "Thou" is free of all confusion and more universally recognised anyway, so using "mil" is just a bad choice.

    I use "thou" in verbal communications and almost always use 0.001" numerals in written communications.
     
  8. Adjuster

    Well-Known Member

    Dec 26, 2010
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    In the UK, "thou" was generally used, and still is for work in inches. "Mil" is likely to be taken for millimetre, and indeed I can remember some confusion arising over CAD software for PCB layout. We had an American salesman in to the office to explain his company's product, and he was quite taken aback when someone asked about tracks a fraction of a mil(limetre) wide.
     
  9. steveb

    Senior Member

    Jul 3, 2008
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    I use mil for short, and thousandths of an inch to avoid confusion with people that might not know the meaning. I'm not sure why, but I rarely hear the term thou, until I go to church. I hear thousandths more often, and we always know it means thousandths of an inch.

    I'm in the USA, where the metric system is still only common in engineering and science. One of the rare exceptions here is the 2 liter bottle of Coke or Pepsi. We'll buy a 1/2 gallon of milk and a 2 liter bottle of coke on our way home from work. - Don't know why that is.
     
  10. atferrari

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    Never in my case! Always seen them abbreviated as mm the way it is taught at school in our metric country.
     
  11. THE_RB

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    It's very common in Australia where we have been working in mm since the 70's (and are culturally prone to lazily abbreviate) to say things like "that's a couple of mils too big" meaning mm.

    Also "mill" is a very common piece of equipment, AND a common workshop verb, that just happens to be closely tied with measurements.

    "Mill (verb) off a few more mils (unit) on the mill (noun)"... ;)

    I'll stick to "thou" thanks.
     
  12. debjit625

    Thread Starter Well-Known Member

    Apr 17, 2010
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    Agreed.
    It may be milli or mm ,never heard mil used as millimeter.

    I know "Thou" was used by Shakespeare ,I learnt that in school.Even if you search google the first result is english pronoun...
    http://en.wikipedia.org/wiki/Thou

    If you search Mil it will give you this page of wiki,were under the section "unit of measurement" its written...
    http://en.wikipedia.org/wiki/Mil
    Anyway people will go with their own systems and that makes everything more confusing.And we can't deny that so learn all the units...
     
  13. Sparky49

    Active Member

    Jul 16, 2011
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    I often hear people using 'mil' as a reference to millimetres.

    If someone shouted to me "I need 20mils cut of this", I'd take that as 20mm.
     
  14. #12

    Expert

    Nov 30, 2010
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    I have never heard, "thou" except in The Bible. That's why I didn't check this thread for weeks. But then, I am not a machinist.
     
  15. BillO

    Well-Known Member

    Nov 24, 2008
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    OOOhh! That would be a big error.

    20mil is about 1/50 of an inch, 20mm is about 4/5 of an inch.
     
  16. GetDeviceInfo

    Senior Member

    Jun 7, 2009
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    with a mechanical background, 'thou' was the term used in Canada. In the late 70's we converted to metric and millimeters was thrown around, but 'thou' made it clear what one was referring to. I never trusted the term 'mil', or to be more clear, trusted the source using the term. I admit ignorance on my behave, but I always triple checked, or sought a stated 'thou'.
     
  17. QuadTech

    New Member

    Apr 19, 2011
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    You have to understand the audience you are talking to. Are they going to assume that mil means millimeter? You want to make sure what you say and what they hear are the same thing.
     
  18. THE_RB

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    Feb 11, 2008
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    That brings it back to my original point! When there are two terms that mean the same thing, thou and mil, thou works very well while mil has a LOT of problems.

    We don't need two terms, so eliminate the BAD one and just use thou from now on.

    If you use thou nobody will think you are talking about a Mill (milling machine) or a Mil (millimeter) or a verb (to mill) or an abbreviation of Military (Mil spec) etc. Mil is a REALLY bad term to use for a measurement in thou(sandths) of an inch. Get over it, move on.
     
  19. Wendy

    Moderator

    Mar 24, 2008
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    Given that mil is the industry standard for my profession, good luck with that. It is not happening.
     
  20. debjit625

    Thread Starter Well-Known Member

    Apr 17, 2010
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    Me too. I am ok with "mil" and really not much people around me understand "thou".
     
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