metric vs imperial systems

[dan610324]

in sweden they are 45x95

[GGaskill]

So even in the heart of metric land, the actual sizes aren't an easy to use 50x100 but 45x95.  Not many factors of ten in those numbers.   

By the way, 16/32 was a typo; should have been 15/32.

[carronader]

Gary .....how do you know your sights are marked in Arshins    an Arshin is Russian step , pace.    Russians wouldn't write Arshins in English script   it would be like this ' аршин '                                  нщг огые пще ьу сгкшщгыю 

[Double D]

Mosin rifles don't go here even disguised a 7.65 cannons

[RocklockI]

Well , I bet they aimmed their Unicorn cannons in Arshins too ......

Gary

[gulfcoastblackpowder]

So even in the heart of metric land, the actual sizes aren't an easy to use 50x100 but 45x95.  Not many factors of ten in those numbers.   

By the way, 16/32 was a typo; should have been 15/32.

What's more, saying you need to buy a fifty-by-one-hundred takes a lot more effort than a two-by-four.

[Cat Whisperer]

whats the difference between 1/2" and 16/32" ??

Dimensionally, no difference.

BUT, plywood that once was 1/2" (or 16/32") is now slightly thinner, 15/32.
How many mm?  12.5 or 13?

[GGaskill]

.50 cal is 12.7 mm so the 15/32" is really close to 12 mm (11.906 mm, less than .004" difference.).

[dan610324]

yes 12 it is

the best so far is that 1" is 3 barley grains long

anyone who know what one meter is ??
its actually 1/10 000 000 of the distance from the north pole to the equator 

but all antique drawings are messured in calibers , so there we got a third way to messuring things 
all smaller messurements are shown in 1/16 part of the bore
so all astragals and fillets are most often 1/16 bore diameter wide
thats something to think about if you are designing your own barrel

[Victor3]

There is a vast investment in imperial based machinery in American industry.  Changing it all to metric just for the hell of it makes no sense.  On top of that, there are industrial standards that govern things such as thread pitches versus fastener diameters.  Even within the metric world, there are several differing ones.  So switching to the use of metric measurements does not make everyone in the world compatible in everything.

 What vast investment in inch machines are you speaking of that can't either already be used to make metric parts or be cost-effectively adapted to do so?

 Most of the 100's of older conventional machines still online at the factory I work at were originally designed in inches but we now make a mix of mm & inch threaded/dimensioned parts on them. The gears, cams, dies, cutting tools, etc. used with them are generally perishable items that are all made in mm today at no higher cost. Inch/mm doesn't matter to a CNC or to a conventional fitted with a DRO.

 ISO Metric threads are used pretty much universally on all new-made stuff, so interchangeability won't be a problem for much longer. ISO M series already mates with some of the popular obsloete metric threads anyway.

 I don't think other countries changed over "just for the hell of it." Musta been some kinda financial incentive to do so. We in the US seem to be the only dinosaurs that don't know we're extinct yet.

[carronader]

the UK fought long and hard to keep Imperial   but it's a requirement of European Union to use Metric. it makes sense really when you have one system for trade and manufacturng. Financial penalty if you didn't accept it. UK had to enforce it, Frogs were pushing for penalty over Uk dragging it's feet. Worked out ok for me  I can measure in Yank and Frog. If you are working with old Dutch..German ..Russkie drawings you will soon find out the benefit of one system , you got to be so carefull with scale and proportion, while I'm on that point........with old drawings....Check  Check  and check again  lots of these drawings must have been done by artists , amateurs or total idiots   proportion of wheel to trail -  barrel to wheel -space between trails to accept full width of trunnions ( when twin trail )  (cheeks when single trail)  trust nothing         wood has this bad habit of staying cut.   metal is same.

[Victor3]

 At least some of the younger folks in the US are starting to understand the value of the metric system...

http://www.theonion.com/articles/metric-system-thriving-in-nations-inner-cities,458/

"For some unfathomable reason, the U.S. is the only major industrialized nation in the world not using the metric system," said Dr. Michael Lenzi of UCLA's Center For Statistical Data. "At long last, it appears that the metric system is being embraced by a progressive segment of the population outside the scientific community."

[Terry C.]

I was shaking my head at that article, until I noticed it was from "The Onion."

Sadly, though, it's not that far from the truth.

But fear not, Imperial System, for there is hope! The gangstas would be lost without their Glock "fo-tays" in their waistbands (which is generally about mid-thigh).

[gulfcoastblackpowder]

I was shaking my head at that article, until I noticed it was from "The Onion."

Sadly, though, it's not that far from the truth.

But fear not, Imperial System, for there is hope! The gangstas would be lost without their Glock "fo-tays" in their waistbands (which is generally about mid-thigh).

The cookie test was cut short by the disappearance of 25 scales, but results are still being called "conclusive."

 

[Cat Whisperer]

...
"For some unfathomable reason, the U.S. is ...."

The reason can be understood in one word: congress.

Edit:  oops, sorry for the out of place winging about politics.

[BBF]

is there any easy way to learn how it works ??

No easy way at all, but we do expect the entire world to switch to imperial and do it immediately.

Mixups between metric and imperial is the reason the Hubble telescope was screwed up the first time around.

I presume you know that the Imperial measurements are not the same as the American ones in several cases. ie gallon quart,pint, fld oz, tons that come to my mind right now.

[BBF]

I remember Whitworth spanners (wrenches)  were in fractions   damn useless   could always find one or two in peoples toolbox   were only good for hammering onto a rounded nut or bolt. Always big , heavy made. 

Whilst metric and Standard(US) wrenches are measured to fit the opposite flat sides of a bolt head. The Whitworth are measured from the opposite pointy sides and are meant to be used with Whitworth fasteners. A good example would be the old British Seagull Outboards. 

[dan610324]

seagull ??
is that a more powered outboard engine than the evinrude ??
I remember the evinrude from disneys bernard and bianca

or is it a smaller type plane from albatross airlines 

[GGaskill]

The real reason we haven't completely converted to metric is that it really offers no advantage.  Inch screws and bolts work just as well as metric ones.

[dan610324]

yes they do ,
as long as you dont stand in the middle of nowhere in a "metric" country and need spare parts

so a world standard would be good , metric or imperial really doesnt matter
but as it is just usa and burma who uses the imperial today it would be easier to change to metric

[Artilleryman]

Back in junior high school I was told by my math and science teachers that the US would convert to metric within ten years.  Each year as I went through high school and then college I was told the US would convert within ten years.  Fifty years later....................

[dan610324]

yes , why change something thats working
but I guess that also usa will change to metric
maybe not as long as we are living
everything comes closer and closer to world standards

[Victor3]

so a world standard would be good , metric or imperial really doesnt matter...

 I beg to differ, Dan...

 The Metric system has only 7 basic measures. The Imperial has over 300 and they are often ambiguous.

 If only for simplicity's sake, we in the US should get with the program.

[dan610324]

yes I prefer the metric system , but Ive been brought up with it so all feel natural and logic to me
could be different with you americans I suppose
now when you mention those figures I really dont understand why you still use it
but ok Ive also seen discussions here at the board where native americans seem to have had problems to really understand it a few times
so I guess that I dont need to be ashame when I need to think twice sometimes and even use the calculator to really understand what you are talking about

[Cat Whisperer]

Exactly.

(Most of us have been cussing fractions for our lifetimes!)

When I was a professor, I could readily tell which of my older students were machinists and which were tool makers - just by their knowledge of fractions.  I.e.: did they know the decimal equivalents of 16ths, 32nds or 1/64ths.  That instantly told me the level of accuracty they routinely delt with in their experiences.

[Zulu]

Iv'e only been cussing them for about 2/3's of my life.
Zulu

[subdjoe]

so a world standard would be good , metric or imperial really doesnt matter...

 I beg to differ, Dan...

 The Metric system has only 7 basic measures. The Imperial has over 300 and they are often ambiguous.

 If only for simplicity's sake, we in the US should get with the program.

yeah!

Now, how many femtograms of H380 do I need for a 7.69 Brit, 11.7 gram RN, to get it to 701 mps?

[BBF]

You could use 2.83 grams of Norma 203 for 774 m/sec

  Man !! There are manuals out there in metric.

[GGaskill]

Well, the original question was how many femtograms ....  But with the metric system, it's just a simple shift of the decimal point (after you look up what a femto- is [10^-15]); 2.83 x 10¹⁵ femtograms (although an inappropriate unit for this quantity.)   

[dan610324]

thats real bs , femtograms is a non existing unit in practical use
maybe in theoretical higher math

smallest unit used is gram , 1 gram is 15,43 grains I think

for smaller weights you just use 0,00076 for example
or milligram = 1/1000 gram but who actually use that ?  microgram is smaller
I will never open any drug factory