Talk:Pound-foot (torque)

“exactly”

The “exact” form in this version of the article is not exactly that value. The value was given as 1.3558179483314004. Carried out to a precision of 100 digits, the value is 1.355817948331400399999999900459473744029708329461580973429590812884271144866943359375. It will appear to be equivalent to a certain number of digits to 15 to 17 digits on most computers that simply rely upon double-precision math, which is built into most microprocessors’ math libraries. However, it won’t repeat for many tens of thousands of digits. I’ve corrected this. Greg L (talk) 21:41, 24 September 2009 (UTC)

Yeah, great to know that a 14 digit approximation isn't good enough for some applications. Why anyone with any scientific ambitions use this unit is beyond me. -- Henriok (talk) 13:59, 1 October 2009 (UTC)

Greg, I'm not sure where you get your value but I do get 1.3558179483314004 N·m exactly. If a foot is 0.3048 m, a pound is 0.45359237 kg and standard gravity is 9.80665 m/s², this is what we get ... exactly ... or should we not be using the CGPM value for g? JIMp _talk·cont 05:27, 13 July 2010 (UTC)

Of course, the 17 digit value is exact, since foot, pound and standard gravity have each exact values in SI units with a few digits only (1 ft = 30.48 cm by definition..) Your lengthy 100 digit number is wrong, it’s just the result of Floating-point_arithmetic#Accuracy_problems. Wassermaus (talk) 06:46, 7 June 2022 (UTC)

Importance scale

I rated this as 'Top' importance - a must-have for a print encyclopedia. This helps the article get into projects like the Wikipedia CD for kids. As far as I can see, all commonly used units of measure should be in print encyclopedias - they are in most of the sizeable ones I have seen. Anyone who picks up a spanner or a wrench in the English-speaking world should be aware of the pound-foot, even if they don't know much about it: they will see it and the Nm mentioned in the glovebox handbook of every car.

I disagree with the reassessment as 'low importance'.

--Hroðulf (or Hrothulf) (Talk) 12:49, 28 November 2009 (UTC)

I disagree with the assessment of this article as there is no credible citation as to the existence of the word “pound force”. Because “pound force” appears in media adds to sell cars or automobile owner’s manual does not mean it is a legitimate word demanding the attention of Wikipidia.Greg Glover (talk) 16:26, 24 July 2010 (UTC)

I agree that this should be high-importance as well. However, I don't think I'm an expert, but if I cite a bunch of math textbooks, you guys can edit it. 199.17.228.129 (talk) 16:06, 22 April 2014 (UTC)

Um, nevermind, I thought this was the only article on torque, and I also forgot to login earlier... Cammy169 (talk) 16:12, 22 April 2014 (UTC)

Where did this "pound foot" term come from?

Can someone please cite the origins of pound foot. I see no citations or wikilinks.

I do not see this word in my Webster's Unabridged Dictionary and it does not appear as a unit of measure within English units, Imperial units or United States customary units.

If no credible citations can be made I move to have this artical removed from Wikipidia.Greg Glover (talk) 16:10, 24 July 2010 (UTC)

Citation added. Hqb (talk) 17:47, 31 July 2010 (UTC)

Again, kudos Hqb,

you have referenced the first known use for the pound foot here at wiki. However as stated on the Foot-pound (engery) Disscusion page, the pound foot is not and never has been, a recognized unit of measure. Therefore, this page and the word usage should be and is demanded by Wiki standards to be removed form all articles if cited as a unit of measure. I’m sorry but at this time my personal feeling is that your citation in not credible. Maybe others will disagree.

—Preceding unsigned comment added by Greg Glover (talk • contribs) 22:38, 31 July 2010

Move page

Greg Glover has suggested moving this page to Foot-pound (torque). Yes, no, maybe so? Rracecarr (talk) 20:46, 4 August 2010 (UTC)

Agreed. Nobody says pound-foot. MarcusMaximus (talk) 03:36, 6 August 2010 (UTC)

I would just like to say that NIST does consider a "pound-force foot" (lbf-ft) to be a unit of measure for moment of force (reference sp811 on the use of SI Units). I agree, though, that the term is not as good as "foot pound." And the same NIST publication also lists "foot pound-force" as a unit, so I think we can stick with that. — Preceding unsigned comment added by 74.218.129.74 (talk) 19:18, 5 February 2013 (UTC)

Foot-pound

This was removed on the grounds of original research [1]

The alternate name "foot-pound" (ft-lb or ft-lb_f) is also used to refer to this unit; for example, in the United States, the torque created by automobile engines may be quoted in foot-pounds.<ref>{{Cite web|url=http://www.international.fleet.chrysler.com/news/articles/minivan_anniv.html|year=2008|title=Chrysler LLC Celebrates 25th Anniversary of the Minivan|publisher=Chrysler|quote=... the segment's best combination of horsepower (251 hp) and torque (259 ft.-lb.).}}</ref>

A direct reading of a primary source as I did is not original research in the meaning we normally use at Wikipedia. I simply found a reliable source in the US motor industry that used the name 'foot-pound' to publish the torque of an engine. I am not claiming that the Duke of Oxford wrote Shakespeare plays. I think that if you delete something on the grounds of no citation, you need to hold a reasonable doubt of its accuracy. If you really think it is untrue, then by all means delete it but please put your case here. The "NOR" principle is for dispute resolution, but I don't think that we have a dispute here, as everyone who edits this article is aware that the term ft-lb torque is used occasionally, even though we haven't read a linguistic analysis of where it might be used in a textbook or other secondary or tertiary source.

Just in case they help the discussion, I have found a couple of uses outside the immediate context of the US auto industry:

• MIT course notes "Units of torque ... 1 ft·lb = 1.356 N·m" [2]
• McGill course notes " Converting the information into the units of the World (outside the US), a ft-lb (that is a foot-pound in real English) becomes 0.305m times 0.454 kg or 0.1386 kg-m." [3](p14)
• DePaul course notes "The data are on gas mileage (miles/gallon), motor displacement (cubic in), horse power (ft-lb), torque (ft-lb) ..." [4]

Also these workshop books are in the context of the US motor industry:

• Popular Mechanic, Oct 1956 "Torque usually is expressed in ft.-lb.," [5] (p245)
• "However, it is rather common to see torque stated in terms of foot-pounds (ft.-lb.)" (Erjavac 2011 p38) [6]
• "Torque is measured in foot-pounds or inchpounds." (Gills 2011 p896) [7]

Please restore at least the part of the sentence that reads "The alternate name foot-pound (ft-lb or ft-lb_f) is also used to refer to this unit;" though I think the 'for example' clause is also justified.

--Hroðulf (or Hrothulf) (Talk) 22:26, 7 November 2011 (UTC)

I restored the sentence about ft-lb of torque. This is not original research, it's a primary source. Also, the OR page says

That "Paris is the capital of France" needs no source, because no one is likely to object to it and we know that sources exist for it.

MarcusMaximus (talk) 07:50, 9 November 2011 (UTC)

Good effort, but misdirected; you should have added at least some of the valid sources you found to the article. Listing them on the talk page as you've done here amounts to dropping a pile of papers on the floor and declaring that somebody oughtta come pick 'em up and make use of 'em. I'm cleaning up your mess this time, because the goal here is betterment of the encyclopædia, but next time try and do a complete rather than halfway job of finding and providing apposite refs, please and thank you. I don't care to get in a tiff with you over what you believe you understand of Wikipedia protocol related to original research, primary sources, and questionable assertions. —Scheinwerfermann ^T·_C17:41, 9 November 2011 (UTC)

I don't care to get in a tiff either.

More importantly, I like your version of the article much better than the version that started all this so it was time well spent.

--Hroðulf (or Hrothulf) (Talk) 21:22, 9 November 2011 (UTC)

"f" in the pound-force symbol

"lbf" (sometimes with f as a subscript) is a well-known symbol for pound force. Today's edit summary [8] suggests it is somehow improper or incorrect in the context of this article, and I am not sure why.

I took a quick confirmatory look with a search engine and found these. We can of course allow that publishers may get it wrong too, but I would like to understand why.

• Keating, Eugene L. (2007), Applied combustion, p. 348, Brake torque, τ, is the product of a moment arm and corresponding brake force or, τ=rf N⋅m (ft⋅lbf) {{citation}}: Unknown parameter |vol= ignored (|volume= suggested) (help)
• "D1043-02", Annual book of ASTM standards, American Society for Testing and Materials, 2007, p. 225, T = applied torque, N·m (in.·lbf),

--Hroðulf (or Hrothulf) (Talk) 20:24, 10 November 2011 (UTC)

Please go take a look at Foot-pound (energy). —Scheinwerfermann ^T·_C21:44, 10 November 2011 (UTC)

Scheinwerfermann, can you explain what in particular we are supposed to look at in the Foot-pound (energy) article? The ft-lb unit of torque should use the pound force (lbf) as well. MarcusMaximus (talk) 08:12, 11 November 2011 (UTC)

Our job in writing an encyclopædia is not to write articles aimed at correcting reality to what you or I or anyone else thinks "should" be the case. —Scheinwerfermann ^T·_C19:06, 11 November 2011 (UTC)

That extremely general statement doesn't help me figure out what you're talking about when you say "Please go take a look at Foot-pound (energy)." Can you please be more specific about which part of that article answers Hrothulf's question about the f in lbf? MarcusMaximus (talk) 05:50, 14 November 2011 (UTC)

I don't understand why a user is setting treasure hunts for us. Engineering textbooks use 'm' and 'f' suffices or subscripts to distinguish between pound mass and pound force. Therefore MarcusMaximus and I, and the editors of the Foot-pound (energy), have concluded that Wikipedia should do the same. Let's restore the 'f' suffices. --Hroðulf (or Hrothulf) (Talk) 17:03, 16 November 2011 (UTC)

Agreed. I have restored it. MarcusMaximus (talk) 06:19, 17 November 2011 (UTC)

Plurality

I've been trying to find a source to explain the proper handling of English pronunciation with regard to the plurality of this particular term, which is very frequently spoken and written as "pound-feet." I'm hoping we could add a section to the main article clarifying the proper usage given that this term in particular is so frequently pluralized from pound-foot into pound-feet. I suspect foot->feet is not correct, however, even if it is, the inconsistency I observe begs clarification for those who care to lean the strictly correct usage (strict as opposed to "accepted to due to frequent usage over time").

In English it would be cumbersome to pluralize the pounds part, so that's not very common. With that said, is it grammatically proper to do it that way? Maybe we're supposed to be saying one-pound-foot and two-pounds-feet (pluralizing both)?

There are eight permutations of the phrase and I expect exactly two to be correct (one for singular, one for plural):

• singular
  1. one pound-foot
  2. one pounds-foot
  3. one pound-feet
  4. one pounds-feet
• plural
  1. two pound-foot
  2. two pounds-foot
  3. two pound-feet
  4. two pounds-feet

In terms of relevance, I think my question bears discussion here on Wikipedia (hopefully consensus via citation). When removing Wiki from results, the #1 reference for either phrase is this blog post where, notably, the very first comment touches on my question here (how to properly pluralize?): https://macsmotorcitygarage.com/foot-pounds-and-pound-feet-whats-the-difference/

thoughts? I'm a total wiki noob trying to add to the discussion and value of the ecosystem here in this talk... proactive apologies if I'm doing it wrong!

Dsuchter (talk) 14:13, 27 May 2018 (UTC)

You ask a very good question. I have seen pounds-feet and foot pounds both used. I don't think you will find an authoritative source either way though because it's a free for all (national and international standards bodies deprecate use of both the foot and the pound-force, leaving a standardization vacuum). As an author if found myself using these units I would steer clear of the plurality problem by using only the symbol lbf ft. Does this help? Dondervogel 2 (talk) 16:30, 27 May 2018 (UTC)