1
$\begingroup$

Is the term "English units" still in current everyday use? I do hear this term among other engineers I work with but I'm unsure if this is a localized usage or is consistent with the wider community.

Mainly I'm focused in the HVAC field but I don't know if terminology would be different in other areas. I noticed that ASHRAE uses the term "IP" or "inch-pound" to refer to what could also be called "English" units, e.g.:

"The ASHRAE Handbook ... is available in I-P (Inch-Pound) or SI (System International) units of measurement."

Formerly I had thought "US customary" was the appropriate term to use.

There might be some subtle technical differences among how "English", "IP", "US customer", or any other scheme is defined. But what I'm interested in is understanding which term mechanical engineers are likely to use in everyday discussion or writing where those technical differences are generally not relevant.

I don't have the impression these units are widely used outside the USA, but I do have an international "audience" in mind so international differences would be interesting, if any.

$\endgroup$
2
  • $\begingroup$ US Customary units is the correct name. They have not been legally acceptable units for any commercial purpose in the UK for many years now. I guess a US organization like ASHRAE prefers to call them "English" to hide the fact that only one country in the world still uses them - and it's not England.. $\endgroup$ – alephzero Jun 14 '19 at 15:13
  • $\begingroup$ @alephzero ASHRAE is calling them "Inch-Pound", not "English" $\endgroup$ – StayOnTarget Jun 14 '19 at 15:41
2
$\begingroup$

The term "English Units" might be confusing, especially with the English and American...

I believe the term is "Imperial Units" for those in the UK, but not sure how other countries refer to them.

Gallons are defined as US or Imperial and have different volumes. But a gallon does have different volumes in history anyway...

Inch-pounds is a "standard" name, as well as foot-pounds, both used on torque wrenches smaller and larger.

$\endgroup$
3
  • 1
    $\begingroup$ The term in the UK is "obsolete units." There are UK-born people who are now in their 30s and 40s who don't even know how big they are, because they were never taught them at school and never use them (except for a very few exceptions like miles for road distances and pints for beer) $\endgroup$ – alephzero Jun 14 '19 at 15:18
  • $\begingroup$ @alephzero yes, and some of the current generation don't even know the current units... $\endgroup$ – Solar Mike Jun 14 '19 at 15:19
  • $\begingroup$ You are correct that the term in the UK is "Imperial Units". However these have limited statutory acceptance, and this is unlikely to be changed by the UK leaving the EU. $\endgroup$ – Mark Morgan Lloyd Dec 21 '20 at 19:03
1
$\begingroup$

I teach the American Engineering system.

https://www.learnthermo.com/T1-tutorial/ch01/lesson-B/pg04.php

I see references also to it being called the English Engineering system.

https://en.wikipedia.org/wiki/English_Engineering_units

At one point, I remember being taught the inch-pound and ft-slug systems. I imagine the former could still be common in systems where pressure is expressed in pounds per square inch (psia or psig). An analogy is the use of the cgs (centimeter gram second) system by chemical physicists to avoid large exponential factors that would arise otherwise with the mks (meter kilogram second) system

$\endgroup$
0
0
$\begingroup$

English units of measure are no longer used in England. Understanding the history of American independence and British colonial rule will clarify their origin.

Prior to American independence the imperial units were used. After independence the use of American imperial units changed according to American standards independent of British imperial units. This explains why US gains are not the same as British gallons.

When UK adopted ISO standards officially, all English measures in engineering became metric standard however, US Imperial measures still remained in use on American soil while rest of the world uses metric based measures.

This is why US imperial units are called English units when in fact they are actually American.

This explanation was given to me by my Civil Engineering head of department at University of Wolverhampton, England where I am a student of civil engineering.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.