How should we describe non-metric tooling?

[SandgrounderParticipant @sandgrounder]

I worked as a Draughtsman both before and after metrication and the latter was a Godsend, I found working with fractions was a nightmare especially on some of the American drawings we had to use, to find a particular length might require adding four or more dimensions such as 1-19/64" , 11/16", 3-17/32", 2.183" etc together and this was pre-calculator days.

John

[Michael GilliganParticipant @michaelgilligan61133]

For those with iOS devices …

'Fraction Calculator Plus' by Digital Alchemy is a little gem of an App.

… There is a free [Ad-supported] version if you're worried about spending 49p.

Hang the expense; buy 'Calculator Plus' as well.

MichaelG.

[Maurice Cox 1Participant @mauricecox1]

Reading this post reminds me of an incident, when I had my gutters and facials replaced. It was a two man team, one of them had just left school. At one point the older chap called down for" one and a half metres of the six inch". A short time later I said to the school lever that I realised that the other chap was his boss, but he wasn't doing him any favours by mixing metres and inches. His reply? "What's the difference?". I went indoors to cry!

Maurice

[Neil WyattModerator @neilwyatt]

Posted by pgk pgk on 01/06/2017 14:06:21:

Havng read this read I feel bound to ask what i should ask for when buying mint imperials…?

Two ounces, unless you have false teeth, in which case you can have a quarter, but you will have to suck them.

Neil

[Chris GunnParticipant @chrisgunn36534]

I went into our local Wickes last week, and saw the small tape measures they have for sale in a jar at the till. I noted they were metric so asked the till operator if they had them in imperial. "what is imperial" she asked, I said the units on the tape are in feet and inches instead of metres, "what are feet and inches" she said, at which point I gave up.

Chris Gunn

[MuzzerParticipant @muzzer]

Despite having used them professionally for the best part of 30 years, I didn't realise that SMT compts are actually available in both metric and imperial descriptions. So you could specify an 0603 compt (imperial) and end up with a metric one with 40% of the linear dimensions. I've worked with them in most major markets (US, EU, Far East) yet never come across "metric" ones. You live and you learn…

Murray

[Stuart BridgerParticipant @stuartbridger82290]

I learned metric at school in the 70's. Had to then learn Imperial during my apprenticeship, where the majority of projects where still in inches. I am happy working with either. I have dual dials on my lathe and a DRO on the mill so swapping is easy. My pet hate though is Imperial drawings other than with fractions. They just are a pain when I am used to working with decimals. I do tend to think in Imperial though. I can visualise 5 thou, 0.127mm just doesn't compute somehow.

[Michael Smith 15Participant @michaelsmith15]

I Have just been making some new wheel studs for a 1929 Crossley truck , the hub end is 3/4 bsf but the wheel nut end is 18 x2mm thread . It would appear that the mixing of imperial and metric has been going on for quite some time

[Raymond Sanderson 2Participant @raymondsanderson2]

Posted by IanT on 01/06/2017 09:05:34:

I don't think of my machines as "non-metric" Raymond.

Simply put they are "Imperial" – they were made that way and will remain so.

I do of course have a few metric tools (albeit they are in the minority) – so perhaps I should start to think of them as "non-Imperial" ?

So that would seem to answer the question but no doubt there will now be a long and heated discussion on the subject – but the sun's shining again outside, life is short, so time to go and do something useful

IanT

Ian I was mid apprenticeship during the change here in Australia one fine student in his last year raced out and bought a full set of metric shifters seriously!!!
At work we still worked imperial building bus & coach frames many chasiss were UK built or some US then in came the Asian such as UD, IZUZU etc all metric. Still all or materials were imperial. Many staff were European or some middle eastern. It was not until the mid 80's steel tubing etc changed to metric, by then I was out of that company but doing repairs at bus & coach co's i worked at. Now trying to explain to bosses why I'd have to build up a gap so panel sheets inside and out would not be uneven as vehicles built prior 80's had imperial tube which was larger.

It caused much trouble in repairing motors, bodies, drivers not understanding 8ft2" width of the body was now 2.48m wide same or that 14ft high was now4.2m these were imperative to know as road bridges clearance signs changed almost over night and as we see here old people don't take well to change.

I hate Metric I snap more bolts and nuts it comes loose more than imperial thread pitch varies between same sizes.

0001thou is better than ??

[Ady1Participant @ady1]

Mars orbiter crashes because of metric imperial woopsie

[Anthony KnightsParticipant @anthonyknights16741]

We are now on the third page of this subject and personally I fail to see what all the fuss is about. I was educated in the 1950's and 60's and was brought up with feet and inches, pounds and ounces et al. I still have a set of Whitworth/BSF spanners from my motorcycling days. The worst thing was the A level Applied Mathematics course with its' Foot/Pounds and British Thermal Units. Then there was Physics,where we used the CGS system. This later got changed to the MKS system, which is all very well, but has led to some ridiculously large or small units which have to be multiplied or divided by at least 1000 to get practical, everyday values.

I have got used to metric measurements and tend to use them most of the time now, although when faced with an unfamiliar value, I have to do a rough mental conversion to Imperial, in order to visualise the length, volume, weight etc.

[Ady1Participant @ady1]

You learn stuff from threads like this

I never knew a chain existed until now and it's relationship to acres(area) as well as miles(distance) and cricket pitches

If I read things right a square acre is 208.7 feet on the side

Edited By Ady1 on 02/06/2017 09:09:31

[Peter G. ShawParticipant @peterg-shaw75338]

Just like Anthony Knights, I was brought up on feet & inches in the 1940's & 1950's. And I suffered with CGS/MKS & now SI, or whatever it's called. I rather think it was in the 1950's that I learned about metric, and since then have gradually changed over to metric such that I now think automatically in metric, indeed it is getting to the state when inches/feet/yards seem somewhat alien now.

The important thing is to be aware that there are these different measurement systems, and to be able to convert between them – if necessary.

One comment about BA. BA is the specification of the entire series of nuts/bolts & threads. There is no need to specify bolt sizes, thread pitches, or anything else – eg 6BA specifies everything – other than length, and therefore all you need are the appropriate BA sized spanners/sockets/whatever.

A storm in a teacup, say I.

Peter G. Shaw

[Speedy Builder5Participant @speedybuilder5]

Ah Ady! Its good to be young as us older ones learnt 22 yards = 1 chain etc etc at junior school, much like our times tables. Can you have a square acre? You may have a square of land which is an acre, but if it were any other shape, it could be an acre.
BobH

[mark costello 1Participant @markcostello1]

Nobody has mentioned the names We give the wrenches (and wenches) when they slip!

[SandgrounderParticipant @sandgrounder]

At least with all these standards they are in English, the Japanese have to contend with "1/4" Whitworth" in their camera manufacturing industry.

John

[Russell EberhardtParticipant @russelleberhardt48058]

Posted by Speedy Builder5 on 02/06/2017 12:32:21:

Ah Ady! Its good to be young as us older ones learnt 22 yards = 1 chain etc etc at junior school, much like our times tables. Can you have a square acre? You may have a square of land which is an acre, but if it were any other shape, it could be an acre.
BobH

Interesting concept a square acre. Now a square metre, or m², is a metre in each of two orthoganal dimensions. A square acre must be an acre² and thus needs to involve the third and fourth dimensions?? Time travel anyone?

Russell.

[SillyOldDufferModerator @sillyoldduffer]

Posted by Ady1 on 02/06/2017 09:06:13:.

…

If I read things right a square acre is 208.7 feet on the side

Edited By Ady1 on 02/06/2017 09:09:31

To be a mega-pedant, each side of an acre enclosed by a square would be roughly:

208.7103255711130359119269739325594232254906391954643105725953202843
11232950189722608720375153033819482364920754087443639804224498009956
08096957429338221015762076482937383115608350391012929148040595218963
09173520879711240464289283710200180944953682561606725329621948176844
97941827390421237419579465909626746184510686264757590949878436627799
56910405162029438631060308690686355005548877608835027208787025477461
32619584965464083310276077445636167361202603866905059156109265411382
7990328478104869507239647431

feet long. This looks suspiciously like an irrational number.

In the US, two different definitions of the yard exist when defining an acre, the yard and the survey yard. Apparently, it's not agreed that the survey yard actually exists. So it's 0.999 998 of an exact yard, hypothetically.

There's never been any particular expectation than an acre would be square; rather the definition assumes certain special rectangles or irregular areas. Better to think in terms of the area that could be ploughed by a yoke of oxen. No-one expects to acres to be measured accurately.

Clear?

, Dave

PS. Aren't expressions like 'square foot' bad grammar? It's surely more correct to say 'foot squared', in which case Ady1's use of 'square acre' is irreproachable.

[James AlfordParticipant @jamesalford67616]

I toddled down to B&Q recently to get some MDF and have it cut to size. I usually work in imperial for this type of job, but took my measurements in metric. It completely threw me when the machine operator, a fairly young person, asked for them in inches instead.

Edited By James Alford on 02/06/2017 17:40:46

Edited By James Alford on 02/06/2017 17:41:15

[GeorgineerParticipant @georgineer]

Posted by Russell Eberhardt on 02/06/2017 15:26:14:

Posted by Speedy Builder5 on 02/06/2017 12:32:21:

Ah Ady! Its good to be young as us older ones learnt 22 yards = 1 chain etc etc at junior school, much like our times tables. Can you have a square acre? You may have a square of land which is an acre, but if it were any other shape, it could be an acre.
BobH

Interesting concept a square acre. Now a square metre, or m², is a metre in each of two orthoganal dimensions. A square acre must be an acre² and thus needs to involve the third and fourth dimensions?? Time travel anyone?

Russell.

Yes , a square acre is a four-dimensional hypersolid. One square acre could be a hypercube with vertices at 0,0,0,0; 0,0,0,1 etc. through to 1,1,1,1. If you want to visualise it you can make a representation in the form of a three-dimensional solid. This is the same principle as representing three-dimenional solids in two dimensions by using perspective drawings.

I suppose you could represent the three-dimensional representation of the four-dimensional hypersolid with a stereo pair of two-dimensional views, but that might be taking it a bit too far.

Geo.

[MuzzerParticipant @muzzer]

I suspect that "twelve feet squared" might actually be 144 square feet? Just a thought….

[Tim StevensParticipant @timstevens64731]

… and all this just because I don't agree that American standards ought to be called 'imperial' …

A strange world indeed.

Tim

[Neil WyattModerator @neilwyatt]

Posted by James Alford on 02/06/2017 17:40:12:
I toddled down to B&Q recently to get some MDF and have it cut to size. I usually work in imperial for this type of job, but took my measurements in metric. It completely threw me when the machine operator, a fairly young person, asked for them in inches instead.

Edited By James Alford on 02/06/2017 17:40:46

Edited By James Alford on 02/06/2017 17:41:15

It was explained to me by an older chap at B&Q who was glad I had metric measurements – in his case the inches scale had worn off!

Neil

[S.D.L.Participant @s-d-l]

Posted by Sandgrounder on 02/06/2017 14:49:24:

At least with all these standards they are in English, the Japanese have to contend with "1/4" Whitworth" in their camera manufacturing industry.

John

Think you will find they have been 1/4 UNC for years

Steve

[duncan webster 1Participant @duncanwebster1]

Posted by S.D.L. on 02/06/2017 21:02:21:

Posted by Sandgrounder on 02/06/2017 14:49:24:

At least with all these standards they are in English, the Japanese have to contend with "1/4" Whitworth" in their camera manufacturing industry.

John

Think you will find they have been 1/4 UNC for years

Steve

Does anyone care? for a low load situation like this it doesn't matter

[Author]

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