Conversions of diameters

Discussion in 'General Electronics Chat' started by RodneyB, Mar 8, 2014.

  1. RodneyB

    Thread Starter Active Member

    Apr 28, 2012
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    I sincerely hope this is the right forum to ask this question. I am making some PCB's and I have a drill plot chart they are 30th and 40th. I assumed it was imperial and looked for a conversion calculator on line. And failed.


    I need to know how to convert a measurement shown in th to mm

    Thanks
     
  2. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
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    hi R..

    (40thou /1000)* 25.4 =1mm

    E
     
    Last edited: Mar 8, 2014
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  3. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    That acutally is times 25.4 ;)
     
  4. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
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    Thanks for the heads up... a silly typo!:(

    E
    Will correct
     
  5. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    Or;
    thou *0.0254
    works just as well and is only one operation. :)
     
  6. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
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    hi Roman,
    The OP appeared in some doubt what a 'thou' is, ie: 1 thousandth of an inch, so thats why I used the 1000 multiplier in order to reduce the 'thou' to inches, 40th *1000 = 0.04 inch.

    Eric
     
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  7. Gdrumm

    Distinguished Member

    Aug 29, 2008
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    If your interested, one of the best simple calculators I've found was written by Joshmadison. Its simply titled Convert. I've used it for several years. It's a small program, bug free, and you can make custom tables with it if you like.

    I hope I didn't violate protocol.

    HTH,
    Gary
     
  8. bertus

    Administrator

    Apr 5, 2008
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  9. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    I use google for most of my conversions, for example type 67 mil in mm and it will give you the answer straight away. And if you use the little search box next to address bar you don't even need to press enter (in firefox at least).
     
  10. Veracohr

    Well-Known Member

    Jan 3, 2011
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    On my computer with Mac OS 10.6.8, dragging my mouse to the lower right corner brings up some maintenance things, but also a simple converter that I often use.

    For more, I use this: http://www.onlineconversion.com/
     
  11. t06afre

    AAC Fanatic!

    May 11, 2009
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    Most ECAD system let you switch between units. Like do your board layout in using the units mils. But then switch to the metric system. Then going over your board with the hole size editor. If that is preferable
     
  12. markdem

    Member

    Jul 31, 2013
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    This is why we should all use the metric system! :)
     
  13. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    Agreed! Everyone but cavemen should be using metric.

    Cavemen can still use bushels and furlongs and sheckels while they scribble email on the cave walls. ;)
     
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