metric to inches

[Frodo]

I am a bit confused.   I can goggle  mm to inches

but.  their is still a difference

like 17mm is 0.69  lol  that is not a clean conversion,

my question is where do i round up or down,

 

here is my measurements i am trying to convert

 

[Northmount]

Buy a ruler with mm and use it to do your measuring.  1" = 25.4 mm.  Nothing neat and clean about conversions.

From your basic math, round up if the last digit you are concerned with is 5 or greater. Round down otherwise.

And if your are trying to convert to 1/16, or 1/8, etc., go back to your basic math and figure it out.

Tom

[zuludog]

Calculating & converting so many individual measurements would be tedious and easy to slip up and make a mistake or two, and rounding up or down would lead to more errors

Easiest would be to just buy a metric ruler - a long and a short one if necessary. And of course, once you have them you'll have them for any future work, leather craft and others

[kgg]

37 minutes ago, Frodo said:

that is not a clean conversion

I feel your pain, there is never going to be a exact conversion between Metric and English measurements. In Canada we often buy items that are weighted in pounds but priced in kilograms, lumber is still mostly English while liquids are metric (1 litre = 1.057 US quarts or 0.88 Imperial quarts). Can get a bit confusing. The best you can hope for are approximate conversion values. The easiest thing is to get a good metric ruler / tape /meter stick (.9144 yards) and forget about trying convert, it will just drive you crazy. Personally I prefer the Imperial measurements.  

kgg

[Northmount]

49 minutes ago, kgg said:

meter stick (.9144 yards)

1 m is equivalent to 1.0936 yards, or 39.370 inches. Since 1983, the metre has been officially defined as the length of the path travelled by light in a vacuum during a time interval of 1/299,792,458 of a second.

Love these base definitions that nobody can understand!

Tom

[chrisash]

Look up

https://www.google.co.uk/search?newwindow=1&source=hp&ei=Nl3bW7vDKdLgkgWK1KzgDg&btnG=Search&q=mm+to+inch&oq=clipart+or+Vector+drawings&gs_l=psy-ab.3...2020.21071.0.21622.27.24.0.2.2.0.88.1618.24.24.0....0...1c.1.64.psy-ab..1.25.1555.0..0j0i131k1j0i22i30k1j33i22i29i30k1j33i21k1j33i160k1.0.iKJMRD0Rj5E

[kgg]

2 hours ago, Northmount said:

1 m is equivalent to 1.0936 yards

My bad, you are correct.

kgg

[Sheilajeanne]

If you are talking about leather thickness, I found this handy chart online, and have it on the side of my computer:

https://www.tandyleather.com/en/leather-buying-guide.html

[mikesc]

"Love these base definitions that nobody can understand!"

Nobody ? ..The "base definitions" are part of physics, the more we understand, the more precisely we can measure..

The base definitions of imperial however.?

Metric is extremely easy to understand..I went through the first 10 years of life with imperial*..horrific fractions and divisions..learned all of them..( including the ludicrous pounds shilling, pence etc ) then discovered metric..( the USA has a base currency of 1ct , and 100 of them to a dollar, no one in the USA counts in 64ths of a dollar, or 8ths of a dollar..or 12ths etc ..you are already working in a currency that uses 100 units every day ..you are nearly there ; ) ) metric measurement is simplicity itself..I can now work in either imperial or metric, but converting them is pointless..just use metric..

*Not all imperial is even the same..US gallons vs UK and rest of world gallons ..

ps..the "base definition" of an inch is ?
https://en.wikipedia.org/wiki/Inch
The base definition of one inch is 25.4mm, it used to be based on the width of a man's thumb, but some of us have bigger hands, and some have smaller hands..My thumbs are 30mm wide ( big hands, long fingers ) my feet hang over the end of "normal" beds..If I asked some one with small hands to make me a bed based on the width of his thumbs, I'd be able to touch the floor with my feet ( my legs from the knees down would be hanging over the end of the bed ) while I was lying down on the bed..My neighbours son is a just a little taller than me, he has to duck to pass under normal doors ( 210cms is a normal door in a modern house here ), but his hands are smaller than mine..so are his feet..which is weird..

Millimetres ( or Millimeters if you prefer ) and the metric measurement system make life easy..and accurate.

Buy a small metric ruler..say 250mm or so..and a bigger one at 500mm and a 1000mm ( 1 metre one ), and a metric carpenters tape and then go around measuring everything, not just leather, you'll soon get used to it..Metric numbers sound bigger, impress the ladies ;)

You are never to old to learn.. :)

Unfortunately screens, lasers, printers etc still use DPI..so for now I can't quite escape having to convert sometimes, my newest laser has a DPI of 500 in the software that it came with..could have been worse..at least it isn't something like a multiple of 72 or 96.

Edited September 12, 2019 by mikesc
typos and grammar

[kgg]

Just to add to the confusion when you by a servo motor you need to know if it is rated using the Metric horsepower or the Imperial horsepower rating. Imperial HP has 745.7 watts and the Metric HP is 735.5 watts. Maybe the horses in the metric countries were a touch smaller and a little less powerful. haha

kgg