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

 

 

[mrwatch]

https://www.engineeringtoolbox.com/inches-mm-conversion-d_751.html

Google Chrome browser will convert for you. Type it in and it asks when you would like. A caliper is also useful for thickness of leather.  

[mikesc]

"Maybe the horses in the metric countries were a touch smaller and a little less powerful. haha "

We had a Shetland pony ( and some other animals ) when we lived near St Tropez, he was about 135 cms at the withers ( or a gnats nudger over 13 and a quarter hands* ) ..pretty big for a Shetland..

French horses small ? ..look up Percheron..
https://en.wikipedia.org/wiki/Percheron
Beautiful, big , powerful horses, I know some people who work with them, logging..

Note what jimmy's online encyclopedia site says about the Percherons ( and their size ) in the USA..

*Hands, another of the imperial "approximate, varied according to where you lived, now "standardised" at 4 inches, or 101.6mm"
or..you just measure horses ( and everything else ) in mm..for precision :)

I measure motors or the energy they use or can give out etc.. in Watts..or Joules..and or / or the "hourly" amounts ..

Hours..24 to a day..10 or 20 per day would be so much more simple..time and astronomical units.."light years"
https://en.wikipedia.org/wiki/Light-year

Not like just "popping out" the the Chemist's** down the road..

**Pharmacy / Pharmacie

Edited September 12, 2019 by mikesc

[CaptJake]

Ask Alexa, that girl knows.

[RockyAussie]

9 hours ago, Northmount said:

Buy a ruler with mm and use it to do your measuring.

As Tom said. Poke ya head out from behind that pine tree in Mississippi and find a hardware store. Great things there await ye

[bullmoosepaddles]

I learned to use metric measure in the machine shop. It is much simpler and more accurate. Easier on the mind when you embrace it. Metric scales of varying sizes are your friend. They are fairly inexpensive. The better one do not live at Walmart. I would suggest a good etched set with cork backing from a office or hobby shop,  

[Sturme]

sorry, but a simple 1 dollar ruler and no more math headache.

[mikesc]

Just realised..even here in metric country, I still buy leather in square feet..The length and width of the piece / skin / hide is given in cm or occasionally in mm..But the price is quoted and invoiced in square feet..Thickness ( weight ) is given in mm.

Go figure..pun unavoidable.

[RockyAussie]

6 minutes ago, mikesc said:

Just realised..even here in metric country, I still buy leather in square feet..The length and width of the piece / skin / hide is given in cm or occasionally in mm..But the price is quoted and invoiced in square feet..Thickness ( weight ) is given in mm.

Go figure..pun unavoidable.

Yeah same here. Guess 20 square feet sounds better than 1.85 sqm . Its them damn ounces that get me most.

[mikesc]

Tangential, but very important :)..Do you buy draught beer in pints or litres ( or half litres ) in Australia ?..Thinking about the size of your Croc beer holder stuff ( yes, I forgot what you call them ; ) ..

Ounces ( leather "weights" ) I ignore, or transpose to mm thickness without thinking about it now ( work in mm ) ..even carats went metric..1 ct = 200 milligrams, 5 cts per gramme.

What gets me is Engineering thread sizes and pitches, nuts, bolts, screws etc*..and especially old Singer threaded parts..world of their own :(

*Have to have so many tools to deal with British , USA and metric..and some metric used to have weird threads and pitches before they got standardised.

Edited September 13, 2019 by mikesc

[Northmount]

7 hours ago, mikesc said:

"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.

So I guess you can visualize "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."  I can visualize many things, like electrons (or holes if you like) flowing in an electrical circuit, but to visualize how far light travels in 1/299,792,458 of a second is beyond me.  Your definitions for an inch can be easily visualized for a rough estimate.

I have no problems with English (Imperial) or American units, nor with SI units.  I work in all three.  Have taught (for 19 years) engineering/technical folks in both Imperial and SI units for years.  Converted many tutorials, lab assignments to SI units as we adopted SI in about 1979.  Re-derived formulae using SI units.  Have worked in the EPC industry for 20 years using whatever system the client wishes to use.  I can flip back and forth at will.  You should look at Pipe Tables if you want to see a real mess.  No one is ever going to change the dimensions on 2" pipe, nor the threads associated with it.  But 2" pipe is called 2" pipe, though I see some people trying to call it 50mm pipe.  But that should be 50.8mm pipe!  Makes a lot of sense doesn't it!  Also pipe thickness is given as Schedule 10, 20, 30, 40, etc.  No reference to Imperial or SI.  It's just a crazy world.

I still think the best conversion system for those without SI Metric abilities is to use 2 rulers, laid side by side.  Gives excellent visualization.

Tom

[mikesc]

When I visualise that..I rough it to 1/300.000.000 and then imagine "the second" , or the light, if you will stretched out to a seconds worth, and then chopped into 300.000.000 pieces..Might very well not be an accurate visualisation, but it doesn't worry me..I'm happy knowing that ( if we leave aside singularities and so on ) that how far the light goes ( and thus a metre ) is the same everywhere, and not dependent on variations in human digits..( Sorry , could not resist that one ; )

Pipe and pipe fittings here are supplied in imperial, but sold in metric..so yes they do try to sell 2" pipe as 50mm..and succeed..but then most people buying and selling stuff nowadays cannot "make change" without a cash register or a calculator to do the really simple maths for them.

Wood is sold as metric width, metric thickness, but the lengths are all ( in reality) in feet and inches..usually wall battens are 2.40 metres long..which is nearly 7'11"..and if you allow for an average floor board being 1" thick ( 25mm ) you set your joists to 8' vertical separation..and it all fits..But makes for low ceilings in modern houses..our place is older*, so ceilings are higher, which means that replacing battens makes them short, so a lot of adding in extra lengths..and yet "standard" sheetrock reaches nearly floor to ceiling ( allowing for a 30cm skirting board ) makes renovating a PITA.

*This house is nearly a 100 years old, just 50 years older ones can have really low ceilings ( 6' to 6' 6"..or sometimes even lower ), or much higher 10' or 12' ..I put those sizes in imperial so as to make it easier for a majority USA readership to visualise..our entrance doors are low enough I have to duck, but wider than would be normal for their height..I think the carpenter used neither inches, nor metric, looks like he just guessed ( or used his thumbs )..and his apprentice used the apprentice's thumbs, which were not the same ) as the entrance doors are the same heights, but different widths. I have to replace two parquet floors, the boards no longer exist in the original sizes...And to make matters worse when building, cinder blocks were a standard 20cm high, until 3 years ago, when they were silently resized to 19.5cm high, but still sold as the old dimensions, makes for a real WTF moment when you are halfway through working on a long run wall when the change happened.

Back to rulers..I have one steel 1 metre ruler, which when flipped over, is in inches on the other side..and all my tailors measuring tapes have inches one side and metric the other, not planned that way, just happened.My linux machines have "on screen rulers" which have imperial, metric, px, ems ..the windows machines have similar.That is really useful.

I'd go with "holes", any visualisation of subatomics and energy that works, works..even flipping the spin on a hole, or flowing holes, works for me :)..

There are a other ways of thinking of that kind of stuff, but "holes" works :) plus I had a friend, Patrick Woodroffe ( a brother illustrator, sadly dead now ) who wrote and illustrated a story ( along with a large amount of his other wonderful works ) about "The Adventures of Tinker The Hole-Eating Duck"..

Thanks for reminding me of Pat :)

Edited September 13, 2019 by mikesc

[fredk]

The speed of light is equal to the time a traffic light turns green and when the guy behind you blares his horn at you

Mike; here for by length wood is sold in 'metric foot' or meter. The metric foot = 300mm. By volume its sold in the cubic yard, cubic meter or cubic 'metric yard' which is a cubic yard plus about 10%

An easy way to convert US leather ounces to metric millimeter is to multiply the oz by 4 and put in the decimal point in front of the last digit, eg 5oz x 4 = 20, put the point in and you get 2.0mm,  9oz x 4 = 36 = 3.6mm. You are in fact multiplying by 0.4

Converting from and to metric & imperial and back again can lead to serious problems. Thats what happened to one of the Space Telescopes. One group in the US built one part using US Imperial, the group in Europe used metric and both 'rounded' some of the digits in the size conversions thus when the telescope was assembled in space the parts fitted but the optics were ever so slightly 'out'. They had to do an in-space adjustment repair.

Edited September 13, 2019 by fredk

[RockyAussie]

6 hours ago, mikesc said:

Tangential, but very important :)..Do you buy draught beer in pints or litres ( or half litres ) in Australia ?..Thinking about the size of your Croc beer holder stuff ( yes, I forgot what you call them ; ) ..

Since its important and all that - normally 6 packs and sometimes slabs (cartons) and sometimes kegs. The common stubby is 375ml but a little research showed me the following - Aussie population at present about 25 million.

How much beer do Aussies drink?

There were approximately 186 million litres of pure alcohol available for consumption in Australia in 2016-17. This comprised approximately 73 million litres of beer, 71 million litres of wine, 24 million litres of spirits, 11 million litres of RTDs, and 6 million litres of cider.

Oh and we call them stubby coolers and the yanks call em koozie's .

BTW - some of the shiela's whoops.... I mean ladies, here reckon they like blokes (Men) with 6 packs. I reckon why a 6 pac when you can have a whole keg instead?

[Constabulary]

The Guesstimeter is always right - not matter if thickness or length or even volume (cubic guesstimeter)

[noobleather]

Hahhaha loving this thread!!! Ahhhh where to start after drinking a few mililitres/fluid ounces of beer.  As I work on heavy mobile plant in the mining industry,re 250ton trucks (or is that 250tonne) every socket I use is either in metric or imperial.,sometimes there are slight differences in the exact feel of the socket on the nut due to the slight differences between the two. Start leather working and the thickness of leather isn't measured in either but in an imperial weight scale.i need to buy some calipers that show these weights,where can I buy them?

Looking at how many ml or fluid ounces left in my beer glass and laughing.

I guess it's what you get used to.

However metric is easier to add up if you are dumb or drunk,I'm both lol.

Respect to your measuring system.