Metric VS English engineering system of measurement

[Baluncore]

Millers' statements as to the number of sacks, bushels or coombs of corn they have ground are often confusing, and the following may help to light up their remarks. One 'sack' equals four bushels or one coomb, and two coombs equal one 'quarter'; but the avoirdupois weight of a bushel is not constant, thus a bushel of wheat is 63 lb., barley 56 lb., oats 42 lb. and beans 77 lb; so a coomb of wheat is 252 lb. or 18 stone, barley 224 lb. (16 stone), oats 168 lb. (12 stone) and beans 308 lb. (22 stone), and a quarter of wheat is 4½ cwt., barley 4 cwt., oats 3 cwt. and beans 5½ cwt. A 'quarter', avoirdupois, is a quarter of a hundredweight - 28 lb. Beans are 4¾ cwt - 532 lb. - in modem milling. The sack of grain is called a 4-bushel sack'; the term '20-stone sack' (2½ cwt.) is applied to a sack of flour; the coomb is a measure of grain, not of flour.

 

[Baluncore]

There you go. Fixed that for you.

The US will never spell the meter as "metre". Never.

Nevre evre ?

 

[skeptic2]

Pat, working in New York, carries a 50 pound sack of mortar mix up a 20 foot flight of stairs. How much work did Pat do on the sack?

20 * 50 = 1000 foot-pounds

What's so hard ?

I have worked with a number of motor and motor drive manufacturers who consistently refer to the torque of their motors in foot-pounds instead of pound-feet.

 

[gmax137]

I have worked with a number of motor and motor drive manufacturers who consistently refer to the torque of their motors in foot-pounds instead of pound-feet.

Personally, I never really bought into this ft-lb vs lb-ft thing. Seems to me Torque and Work have the same dimensions

[M][L]²[T]^-2

no matter what units system you're following. Does anyone think "meter-Newton" is work and "Newton-meter" is torque? Or should that be "Newton-metre"

 

[PhanthomJay]

Ft-lb is the accepted unit for both torque and work. I have never seen either referred to as lb-ft in the US.

 

[SteamKing]

Torque outputs in the car magazines used to be quoted in units of 'lb-ft' and they still are.

http://www.motortrend.com/roadtests/convertibles/1307_2014_chevrolet_corvette_stingray_z51_first_test/

 

[Baluncore]

I have never thought of “foot.pounds” or “pound.feet” as distinct units.
I still believe that multiplication is commutative.

 

[D H]

Some apparently like to use different names for the units for torque and energy. This distinction with pound-feet for torque, foot-pounds for energy, goes back to 1900. Others don't care. They use foot-pounds for both.

Aside: That distinction seems bass ackwards to me. Torque is $\vec r \times \vec F$, so the units should be feet*pounds to indicate how torque is calculated. Work is $\int \vec F \cdot d\vec l$, so here the units should be pounds*feet. But the convention is the other way around.

 

[WaaWaa Waa]

As was already mentioned in the thread, the metric system is used in the US. So is the old imperial system. You are free to use whatever you like in the US, that's what freedom is all about. ;) Freedom necessarily includes the freedom to make bad decisions, like imperial units. I don't use them though. I use the metric system personally and have yet to have storm troopers knocking at my door.

I recently followed The American Society Of Civil Engineers page in Facebook. I found that they are using only Imperial Units. Now, don't get me wrong. I have nothing against the Imperial Unit whatsoever On the contrary, as a civil engineer myself I applaud the American civil engineers for their achievements using the Imperial Units

 

[SteamKing]

There are a lot of legacy structures which were designed and built using imperial units in the US and in the Commonwealth. There is still a lot of holdover in state regulations and reporting standards regarding public works projects. You have to report the amount of Earth moved in an excavation, for example, in cubic yards instead of cubic meters. Construction materials are manufactured and sold using imperial measures rather than metric.

 

[2milehi]

Torque outputs in the car magazines used to be quoted in units of 'lb-ft' and they still are.

http://www.motortrend.com/roadtests/convertibles/1307_2014_chevrolet_corvette_stingray_z51_first_test/

I wouldn't put too much weight in that presumptuous snob magazine where the readers of that rag never have performed an oil change in their life. Any real gear-head magazine will state ft-lb of torque.

 

[2milehi]

I recently followed The American Society Of Civil Engineers page in Facebook. I found that they are using only Imperial Units. Now, don't get me wrong. I have nothing against the Imperial Unit whatsoever On the contrary, as a civil engineer myself I applaud the American civil engineers for their achievements using the Imperial Units

The surveying tapes are in 1/100 of a foot.

 

[SteamKing]

Land surveying is one of those professions in the US where the law prescribes certain things. Land descriptions are regulated by the various state governments, and the surveyor obviously must comply with those regulations in doing survey work. The US has been surveyed using the imperial system, and the various state plane coordinate systems have also been laid out using imperial units.

When expansion started westward in the late 18th century, the land was divided into square townships which measured 6 statute miles to the side. There were further subdivision in each township, and if you read the legal description of a parcel of land, it will make reference to the township and subdivision within the township in locating that parcel.

 

[xxChrisxx]

To be fair lengths are easy enough to just convert as a design exercise. It's a bit more of a pain to have to own two sets of spanners and sockets.

The true pain in the arse is designing a piece to mate two threaded components together. One with a metric thread, the other with a UTS. Doubly so if they are very similar in pitch, but they still need different gauges.

 

[SteamKing]

That's a big reason why metric conversion in manufacturing took so long. Fastener standards took a long time to standardize across industry, and manufacturers in the US were very reluctant to start the process over with metric fasteners. In the UK, with the Whitworth system, special tools were required which could not be used on US fasteners. Since modern machinery is very dependent on standardized fasteners, this is no small consideration in whether to go metric in your manufacturing sector.

http://en.wikipedia.org/wiki/Screw_thread#History_of_standardization