Metric vs Imperial – Practical or Traditional?

[Chris TriceParticipant @christrice43267]

The essential truth is that a decimal system is undeniably easier to use and to make calculations in. Even Imperial measures get expressed in thou’s. People’s preferences are often sustained by the graduations their machinery is based on and long may individuals have the right to choose (I still use both) but the future is ultimately metric driven by arguments hard to challenge. Does anyone consider the old imperial money system to make more sense than the decimal system? Of course it doesn’t. It’s just what you’re used to.

[WolfieParticipant @wolfie]

Thats a good point, however I would add one more factor. Conveniency.

 

Its convenient to use what you are used to. Its also convenient to use a single value or multiples thereof. Thus for small measurements a thou will always be handier than the millimetre because you will always be talking of a fraction of a mill, however represented. I appreciate that the thou is a fraction of an inch, but it has its own title so until we have the ‘hun’ for 1/100 of a millimetre the thou it is!

 

For intermediate measurements then the mill is spot on and I use it regularly in my other modelling discipline where very small measurements are not required. And for anything bigger its the inch.

 

Its interesting to note that in my plastic modelling world, all the raw plasticard and rod and sections etc that I use in scratchbuilding and conversion are bought in imperial sizes although nearly every other aspect of this genre is metric. So its usual to hear someone saying “I cut a 20 x 40[mm] piece of 20 thou plasticard” And so on.

 

Lets keep both, it clearly works!

Edited By Wolfie on 29/10/2010 11:42:25

[KWILParticipant @kwil]

I note that in many instances, not just in model size, that studs into castings use Imperial threads because the availability of a wider range of suitable coarse threads.

Edited By KWIL on 29/10/2010 11:57:03

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Kwill, indeed this is so, espceialy in industry UNC is very commanly used. As we know a coarser thread is stronger in cast iron.

 

Regards Nick.

[chris stephensParticipant @chrisstephens63393]

Hi Chris,

Yes of course the decimal system is easier, but you don’t have to use the metric system to use it. A “thou” is a decimal unit, remember. 

As for the old money units, there was one instance when Imperial money was far better. When buying animal feed priced in so many shillings per hundredweight you instantly knew how much per Ton!  Oh and another, when petrol was 6/8 per gallon, you got three gallons to the pound, no wait that is not easier just cheaper. I miss the old days.

chriStephens 

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, when petrol was £0 2s11d you could get 6 gallons for a quid and get some change to boot.

 

Regards Nick.

[Axel BentellParticipant @axelbentell]

Posted by Wolfie on 29/10/2010 11:41:15:

Thats a good point, however I would add one more factor. Conveniency.

 

Its convenient to use what you are used to. Its also convenient to use a single value or multiples thereof. Thus for small measurements a thou will always be handier than the millimetre because you will always be talking of a fraction of a mill, however represented. I appreciate that the thou is a fraction of an inch, but it has its own title so until we have the ‘hun’ for 1/100 of a millimetre the thou it is!

 

For intermediate measurements then the mill is spot on and I use it regularly in my other modelling discipline where very small measurements are not required. And for anything bigger its the inch.

 

Its interesting to note that in my plastic modelling world, all the raw plasticard and rod and sections etc that I use in scratchbuilding and conversion are bought in imperial sizes although nearly every other aspect of this genre is metric. So its usual to hear someone saying “I cut a 20 x 40[mm] piece of 20 thou plasticard” And so on.

 

Lets keep both, it clearly works!

Edited By Wolfie on 29/10/2010 11:42:25

 If you want to use something with its own title, use “micrometres” ; 1/100 or .01mm as we should write it, is 10 µm. And that is how its written in most techincal books. A common fraction or decimal fraction is rare to see!

 

[Chris TriceParticipant @christrice43267]

Imperial is warm and comfortable for many because of familiarity. If you were devising a measuring standard from scratch on a clean sheet of paper, imperial is a non-starter. It’s a throwback to a time when a yard was set by the length of a king’s arm and not for any other logical reason. It exists today as a remnant of the only system we had. It’s only convenient to use what you know because it saves you having to learn something new but in a generation or two, 3/16th of an inch will have as much real world meaning as a florin. Metal stockists are going metric because they recognise that’s the way the world is inevitably going. I build replicas that were originally built using imperial materials and it’s getting increasingly difficult to source some of the more obscure bits but I accept the reason and have to move with the times. There’s nothing to fear from metric and indeed much to be gained but you have to be open minded. How many photographers mourned the passing of film but have subsequently come to embrace and appreciate the benefits of digital? The old ways don’t have to die but they are usually kept alive by those who don’t want the change that will inevitably overwhelm them.

Edited By Chris Trice on 29/10/2010 19:42:57

[Ian AbbottParticipant @ianabbott31222]

I liked the days when I could fill my Morris Minor’s tank for, I think, five bob.  This was also when American tourists had no clue about pounds shillings and pence, we’d hang around the castle and “help” them with their change.  

 

Ah, those were the days, it wasn’t always uphill both ways in three feet of snow in bare feet.

 

“Half a league, half a league, half a league on……” 

 

“Point eight two of a kilometre,  point eight two of a kilometre,  point eight two of a kilometre on……”

 

Just doesn’t have it.

 

Ian 

 

 

 

 

 

 

[Ian AbbottParticipant @ianabbott31222]

Sorry, I should have said ” 914.4 mm of snow.”

 

Much easier to visualise isn’t it. 

 

Ian 

 

 

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Chris, I have no fear of metrication, never have had and have been using metric rule measurements since before the seventy’s. Deosn’t mean I’ve got to give up using Imperial.

 

Regards Nick.

[Sub MandrelParticipant @submandrel]

I was in school when they metricated the curriculum.

 

What’s the old saying?

 

Metric for business, thous for precision but imperial fractions for pleasure?

 

Neil

[Chris TriceParticipant @christrice43267]

That’s OK Nick. I’m not suggesting anyone should abandon imperial. I’m just saying that the march to metrication is inevitable and that imperial can not offer any kind of spirited defence other than people who already use it liking it solely for it’s familiarity. It would be interesting to ask those who use DRO’s on their lathes or milling machines, which system they tend to use most or even when using a digital caliper? I like imperial but still tend to work in metric.

[KWILParticipant @kwil]

I have industrial DROs on all my machines and I switch between Imperial and metric just to suit what I am doing. I have a metric Harrison M300 lathe and Bridgeport, but also use them in Imperial. I can feel and see a thou or 5/10ths but I am damned if the same applies to 0.01mm

[Chris TriceParticipant @christrice43267]

Not surprising as it’s just under half a thou but the point is well made. People have a sense for what certain measurements are. That’s the familiarity bit. I’ve found one of the best things for getting a sense of 0.1mm is to compare drill bits that step up in 0.1mm steps. It’s then easier to visualise in your mind what 0.01mm represents. But as mentioned, familiarity with an old system doesn’t mean it’s better than the new. Just familiar. Another example which a few here of my generation can probably relate to. Letter and number drills: I’m sure that to those brought up on them, they’re familiar and easy to appreciate in the minds eye. To me personally, they mean absolutely nothing and the system gives zero indication as to their actual size. It’s completely abstract. If one were quoted, I’d head straight for a set of tables to find out what the ‘real’ size was and use that. Basically anyone over the age of forty will be familiar with imperial being more or less the last generation to use it but there are people I work with in their twentysomethings who stare blankly at me if I throw them an imperial measurement.

Edited By Chris Trice on 30/10/2010 11:25:04

[Chris TriceParticipant @christrice43267]

And another:

 

How many grams in 2KG?

 

Easy Peezy.

 

How many ounces in three stones?

 

Not so easy.

 

How many thou in 7/64th?

 

Brain burp.

[TomkParticipant @tomk39956]

How many thou  in 7/64 easy devide 7 by 64 = 0.1094 rounded to 4 decimal places     

[Anonymous]

Martin,

 

I assume that the terms for the various aviation types definitely came from the nautical world. As did originally the nautical mile. However, it’s use in aviation is probably more to do with the fact that it is approximately 1 minute of arc on a meridian, so it ties in neatly with lat and long, and makes navigation calculations a bit simpler.

 

Regards,

 

Andrew

[Dinosaur EngineerParticipant @dinosaurengineer]

As long as the older American planes are flying, there will be an imperial system which will be quite a few years yet and also camera makers will continue to use Whitworth tri-pod mounting holes in their cameras. I’m sure that there are many other imperial uses/users that will continue for a long time yet.

[Anonymous]

The international air transport system is imperial. Heights, and flight levels, are in feet QNH, which itself is in millibars. Speeds are in knots.

 

Lower down the scale there are of course differences. The US tends to use inches of mercury for pressure settings. Europe uses kph for speed and metres per second for vertical speed. They also tend to use metres for height too; metric altimeters are just plain weird! Airspeed in knots, mph, kph, I can cope with that, but metric altimeters, aaaaargh. It’s even dafter than it appears; I’ve just looked at my low level French aeronautical map of the Alps, and all the heights are in feet.

 

One up to the Brits! 

 

Regards,

 

Andrew

[TerrydParticipant @terryd72465]

Dear Tom K,

 

I’m impressed if you did that in your head as fast as I can work out grammes in a kilo!    Try working out accurate areas or volumes when using feet and fractional inches, my brain explodes every time. 

 

I’m 63 by the way and use metric in preference, despite being expert in imperial including the use of barley grains (3 to the inch when taken from the middle of a ripe ear of barley).  I started teaching engineering metalwork in the early 1970s just as metrication became legally adopted system (before membership of EU) so the youngsters would be in their 50s by now and should be au fait with metrication.

 

Interesting to note that parliament accepted the need for metrication and standardisation in the 1860s but several wars and Conservative MPs got in the way and overruled the scientific and engineering lobby of the day.  One conservative MP even went so far as to object on the grounds that the kilo was too heavy for the British housewife. A greengrocer complained that the pound was convenient as he could pick up a pound of potatoes with one hand – didn’t matter that two handfuls were about a kilo or one hand was half a one.  That’s the sort of rubbish that gets dragged out when entrenched opinion is allowed to rule over logic.

 

As an aside, another less well known fact is that the Florin or two shilling piece  was introduced in the 1840s as the first stage in decimalisation of our currency (1 Florin is 1/10th of a Pound Sterling for our younger readers )  But that was stymied by the same sort of reactionary forces at work (and the Daily Mail didn’t even exist then!).  I think that Toffs hated the thought of the disappearance of the guinea. 

 

By the way Dino engineer, I don’t really care if the Americans prefer to stay in Pre Medieval Europe, it’s about time us who wish to join the 21st century just got on with it. I am of course talking about the inhabitants of the USA not of the majority who live in Central and Southern America

[chris stephensParticipant @chrisstephens63393]

Dino,

Oh yes, like pipe threads, although the continentals leave out the “inch” part and just call it 1/4 or 3/8 with no “, they are he same.

chriStephens 

[Sub MandrelParticipant @submandrel]

I can’t help feeling that, for some of us, using imperial units is part of the whole experience of model engineering.

 

Every hobby has its rituals and paraphernalia – not to exclude those who don’t know, but as a sort of bond for those who do.

 

For me working in imperial means more than just a choice of measurement system (and to be honest I don’t care which I work in, I’m fitting flooring today and decided to work in inches simply because I picked up the old stanley tape which hasn’t got cm on it, not the new one) it means I get to use old stuff and it means I’m using the same system as teh men who built the originals. If I built a French model I’m sure I’d use mm, even if the ednd result is identical.

 

Neil

[chris stephensParticipant @chrisstephens63393]

Hi Terryd,

 “By the way Dino engineer, I don”t really care if the Americans prefer to stay in Pre Medieval Europe, it”s about time us who wish to join the 21st century just got on with it. I am of course talking about the inhabitants of the USA not of the majority who live in Central and Southern America”

 

Tell me, as you want to be in the 21st Century, I must assume that you only make models of Nuclear Power Stations or Fuel Cells or some other “modern” stuff, and never touch anything related to steam engines or other old technologies.

The trouble with being modern is that modern keeps changing, even the metric system. When we started going metric we did not use the SI system but  (if memory serves) the CGS one. How long before some brain box with nothing better to do comes up with a system based on references from “Lord of the Rings”or HG Wells, or to be more modern perhaps “world of warcraft”

chriStephens 

[Chris TriceParticipant @christrice43267]

The last two posts really illustrate the core reasons for imperial within the hobby. The hobby is mostly based around replicating things by a scale factor that were built to imperial dimensions in the first place. It’s a throwback to a bygone era, something we enjoy the nostalgia of. Unfortunately, the rest of the entire engineering world and wider industry is not driven by the emotional but by logical sense. The funny thing is, I mostly build replicas and components for things that are space related but for the same reason in that the originals were built with imperial materials but steam locomotives and traction engines have never been an interest for me. My main job is in the film business building animatronic rigs and that work is 99% metric. The only time an imperial component gets used is when there’s no metric alternative immediately available. Others can source an overlooked M6 screw virtually anywhere, a 1/4″ Whitworth is a struggle even assuming someone has the knowledge to recognise it.

[Author]

Posts