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Australia is being de-metricated!


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Yeah! but its been about 50 years since we (UK) were transitioning from Imp to M. In that time almost every manufacturing system must have been replaced/changed over multiple times.

In Australia we have a tiny market and tiny manufacturing base. We have to supply forward at that small volume, about 1 million new cars per year but we also have to market backwards to keep 20 million on the road, where expected downtime is zero

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we had 7points in the rain gauge this morning.

My USA son in law works with a decimal inch tape measure ie 10 divisions to the inch.

I can still pace an accurate yard; it a bastard now we're fencing in metric.

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I've got an '84 WB Holden 1-tonner that is metric fasteners from the firewall forward in the body and panels, and inch fasteners from the firewall back. The engine and drivetrain is all imperial. Sure makes for interesting repair work.

 

I think I was fortunate enough to go through a schooling system (high school) which ran in imperial measures, but which taught metric measures as well. I can think in both metric and imperial, and slip between the two with relative ease.

I spent all my working life (and still spend my semi-retirement), owning, operating, and repairing plant, equipment and machines that are either wholly American origin or based on American designs.

As a result, the largest percentage of my workshop tools are inch measure tools, and the largest proportion of my fasteners and thread repair equipment is inch equipment. But I do have some metric tools and fasteners.

 

Inch measure stuff isn't going to go away anytime soon, because of the vast amount of equipment, machinery, plant, housing, and other structures, that were built in inch measure, and which use inch-based components.

In fact, a lot of replacement items need to be still made in inch dimensions, so all this stuff can be maintained and repaired.

But I hate it when someone provides the "metric equivalent", which doesn't mate up properly, and which item always seems to be a little smaller in dimensions.

 

Online and phone calculators today do make life easier for the conversions between inch and metric. But I still prefer to think of numerous measures in Imperial measure, such as PSI, it seems simpler.

MPG was easier, I think I've only just got my head used to "litres per hundred kms". What a PIA measure that is. At the end of the day, for the bulk of my fabrication work, I still prefer this measuring device .....

 

SMIDGEON.thumb.jpg.6be8357c2ed534646fef8e8dcfc7899f.jpg

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I always remember when we first arrived in Australia 36yrs ago, I wanted to buy a 6ft length of 4x2. I was told they only had metric lengths and said Ok, I’ll have 2m and they said they only had 1.8m lengths!!!!!

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Pubs are the worst. I go in and ask for a half litre of beer, and get the response ‘ do you mean a pint?’. ‘No, a half litre, 500mls’. ‘How about a schooner?’. And now I’m thinking of a multi-masted sailing vessel where the formast is shorter than the following masts. So I ask, ‘do you sell beer in ‘firkins’ or ‘pins’?, as I now could really do with 1/10 of a pin of beer? And then the barman gets shirty, ‘are you taking the piss?’ No, I say, it seems despite this being a metric country you want to use old British units of measurement. You will find ‘firkins’ and ‘pins’ are real, legitimate, but ancient, measures of beer, like pints. How about some claret instead of beer? ‘OK, a small or large one? ‘WTF does that mean; Do you ever buy petrol by the ‘small or large’? I was more thinking of a hogs head actually.... sometimes it’s just so difficult to buy stuff!

BTW my aeroplane has a wing span of 52 cubits and a MTOW of 3009 D cell batteries.

For those interested in aeronautical units, it’s quite an interesting story as to why UK (& Australian) aircraft ASI is in knots, but the USA use ‘mph’, whatever that is. The answer is about the number of seats in fighter-bombers (money cost), workload and the value of aircrew (human cost). The US didn’t care about any of the costs.

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WAIT

The next french thing to give us the shiitss is their TIME in Metric.

Even the French refused it, Point blank refusal !.

100 seconds a minute.

100 minutes a hour.

10 hours a day

What does this mean for the length of hours, minutes and seconds?.

A second will get slightly shorter. Minutes will be a bit longer.

And hours will take much longer. Metric hours are 2.4 times the hours as we know them now.

spacesailor

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WAIT

The next french thing to give us the shiitss is their TIME in Metric.

Even the French refused it, Point blank refusal !.

100 seconds a minute.

100 minutes a hour.

10 hours a day

What does this mean for the length of hours, minutes and seconds?.

A second will get slightly shorter. Minutes will be a bit longer.

And hours will take much longer. Metric hours are 2.4 times the hours as we know them now.

spacesailor

You forgot the 10 weeks to a month; ten months to a year.

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I'll come back to this discussion later today

 

Let's see why Turboplanner has problems with metric nuts coming loose where UNF ones don't. We'll use this diagram as a reference.

1598959051840.png.88db529a8241146a7400a14f9c503dd1.png 1598959539508.png.2be7632f5cc481a45ad734e93cc43a70.png

Both an M6 and 1/4" UNF have a 60 degree thread angle, so they are the same in that respect. However, we saw earlier that the distance between two successive thread crests are different. For the M6 bolt, the pitch is 0.75 mm, while the pitch of a 1/4" UNF is 0.9 mm.

 

That means that for a thread length of 10 mm, the M6 has 13 V-shaped grooves, while the 1/4" UNF has 11. This means that the depth of the groove of the M6 is shallower than that of the 1/4" UNF. Or to put it the other way around, there is more contact surface between the bolt and the nut for the 1/4" UNF than for the M6.

 

Because there is more contact area, the friction between the surface of the thread of the bolt and the surface of the thread in the nut is higher with the UNF than it is with the M6. With greater friction, the UNF nut cannot release itself as easily as the M6 can.

 

This opinion assumes that both the M6 and UNF nuts and bolts are made from identical metal, and are both tightened to the same torque.

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OME - And with the last sentence, you opened another can of worms - fastener grades and classes, and the differing grades between metric and inch fasteners - and even differing grades between various brands of inch fasteners!

 

Caterpillar utilise a Grade 9 fastener, which is outside "normal" grades of fasteners. This is the highest grade of fastener you can buy, it's 180,000 psi (1240 MPa) tensile strength, and is used for track shoe bolts.

Unbrako manufacture their Allen-head set screws to 10,000 psi (69 MPa) more tensile strength, than the specifications demand, and run wider radii in the thread root, and at the shank-to-head juncture, to make much stronger fasteners.

 

The sites below provide some very extensive information, as regards fasteners.

 

https://www.fastenermart.com/understanding-fastener-grades-and-classes.html

 

https://www.boltscience.com/index.htm?

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Thanks OME, a brilliant assessment and attention to detail.

Things like correct choice of fasteners are often at the base of great products that last a lifetime.

 

OT; That information is just as valuable. the Grade 8 bolts used to assemble the International ACCO were one of it's best selling points compared to the English and American trucks it replaced.

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OME - And with the last sentence, you opened another can of worms

 

You are quite correct in raising a point relating to the tensile and shear strengths of fasteners, but that is further down the track than where we left Turbo with self-loosening nuts (No humour intended).

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Imagine how hard it would be to work out electricity without the metric system. I think even the US uses amps and kW etc.

But...Pints of beer were a corrupted measure even before metrication. In many pubs, a pint is not that big a glass. I find the best way is to ask to see the glass first before you decide on a pint or a schooner... My father used to drink Butchers, quite a small glass, on the theory that a smaller glass refilled more often gave you fresher beer.

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Given the level of expertise here, I can see a new standard emerging.........the Australian Standard Fread (ASF)???

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With the numerous standards already existing - with each one claiming to be superior to the other standards, I see no reason why we shouldn't have another superior standard! :cheezy grin:

 

Something halfway between Metric and Inch measure should suffice, with possibly a few antiquated measures thrown in as well, to satisfy those who believe, "the old ways were best!"

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Seems to me the building trade & supply have never converted - even when its in M its still mostly in the old Imp dimensions

caravans are the same, who designs a window cutout at 914mm by 565 mm or 280 mm by 1524mm. Doors are 622mm by 1823mm/1750/683 high. awnings are sold in feet measurements, alloy cladding covers 254mm deep (10") good fun when trying to get customers to provide an awning length the correct way when they dont want to come in first for me to check.

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Given the level of expertise here, I can see a new standard emerging.........the Australian Standard Fread (ASF)???

Like the NZ switchback.....

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to satisfy those who believe, "the old ways were best!

For the most part, it's not about being best. It's just how it's been done and changing it is more painful than living with it (except whitworth....whitworh can f*ck right off)

 

caravans are the same, who designs a window cutout at 914mm by 565 mm or 280 mm by 1524mm. Doors are 622mm by 1823mm/1750/683 high. awnings are sold in feet measurements, alloy cladding covers 254mm deep (10") good fun when trying to get customers to provide an awning length the correct way when they dont want to come in first for me to check.

That's punishment for owning a caravan. Having a caravan should be as difficult as possible unless you can prove it will never be on the road.....ever. :amazon:

You are quite correct in raising a point relating to the tensile and shear strengths of fasteners, but that is further down the track than where we left Turbo with self-loosening nuts (No humour intended).

You can add another factor with a finer pitch, and that is that finer pitch will result in higher clamping forces for the same torque than a coarse thread, and be less likely to come undone for the same reason.

Given the level of expertise here, I can see a new standard emerging.........the Australian Standard Fread (ASF)???

Good idea....The thread could be made to such wide tolerances that it fits any other similar size and the nut and heads could be 12mm across two flats and 1/2" across another two, with a tapered hex in the middle to fit almost any allen key.:thumb up:

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...That's punishment for owning a caravan. Having a caravan should be as difficult as possible unless you can prove it will never be on the road.....ever...

That's a bit harsh! My preference is that caravans and motor homes be only allowed on the roads between midnight and dawn.

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You can add another factor with a finer pitch, and that is that finer pitch will result in higher clamping forces for the same torque than a coarse thread, and be less likely to come undone for the same reason.

 

That's also correct. It is usual to use UNF or ISO Metric Fine for fasteners that are clamping two items together by passing through the items, or if the bolt is screwing into steel. The force exerted by the nut on the contact surfaces of the items to be held together, which we measure using a torque wrench (or Mk 1 ham fist), can act over a greater contact area between the threads of the nut and bolt. If the materials are metal, a washer of the same diameter as the width of the nut is used as a sacrificial offering to protect the surfaces of the parts being held together. If the nut and bolt are used to join wooden components, a large diameter (penny) washer is used to disperse the force over a wider area to protect the fibres of the wood from damage.

 

If the bolt is screwing into materials softer than steel, we use UNC or ISO Metric Coarse so that there is more material between each thread in the softer material. This prevents the bolt tearing out the material between threads and leaving you with a smooth walled hole.

 

If you want to get right into the nitty-gritty of fastener threads, download this: https://www.swagelok.com/downloads/webcatalogs/en/MS-13-77.pdf

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One aspect of metric measurements that nobody but me seems to find fascinating:

 

The ancient Babylonians (or very likely a much, much earlier civilization) came up with the 360 degree circle;

The French developed the Metric system, which is based on the fact that the earth has a circumference of 40,000km.

 

40,000 divided by 360 is 111.1111111111111...

 

As a geographer fascinated about all aspect of the world, I've brought that little gem to the attention of mathematicians and none have shown the slightest interest.

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That's a bit harsh! My preference is that caravans and motor homes be only allowed on the roads between midnight and dawn.

The fact that most of them are parked up by 5pm for the night is one of the few comforts for interstate truckies.

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Horse floats are worse. They travel in convoys. Nev

That's what caravaners do here. I agree that those towing horse floats are worse, but we have less of them and they are usually just local traffic here, not clogging the main roads in packs.

BUT.

What does it mean, in the real world of things, ?.

spacesailor

Which one? OK's fascination with a certain number or caravaners being c**ts?

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