“F” scale is The Fujita Scale of Tornado Intensity.
(Like a hurricane category)
It is also:
The F-scale is a personality test designed to measure the authoritarian personality. The “F” stands for “fascism.”
You think way tooooo hard John.
Mike,
Still waiting for the answer.
Why is it called “F” scale? Besides the ^%$#$. 
John, so as to indicate that like F-word, it should be avoided!! Best, Zubi
If I recall, it came out of an ill-fated attempt to ascribe letters to each of the myriad scales we model. #1 - 1:32, A - 1:29, H - 1:24, G - 1:22.5, and F - 1:20.3. The “A” was derived from “Aristo” since they were at the time the principle manufacturer in that scale. The “H” came from “Half inch”, the “G,” well…, making “F” the logical letter in the progression. Curiously, it’s one of those terms that’s never really caught on. Even the major manufacturers still refer to the scale as 1:20.3, not “F.”
Later,
K
Let’s not forget “M” (Maine) for 7/8’s scale! :lol:
-Brian
How about if I want to model very narrow, around 1Ft gauge, Industrial on 45mm track…
Let’s see, using a fuzzy metric/English conversion and rounding just a bit, that would be a scale of a real world 1 Foot being represented by .30 inches in the model. I could round that a bit more for ease of calculation to .25" or 1/4" of the model represents 1 real world foot. Going back the other way - scaling up my 1:.25 [notice the decimal point] I get about 14 inch gauge on 45mm track - close enough for this example.
Now, lets pick a letter to represent it - .25 is the same as 1/4 - One Quarter , so how about Q for Quarter Inch. Sounds logical to me.
Now go back and look at NMRA’s Half Inch scale as being 1:24 - There is a boat load of difference between 1:24 and 1:.25, so representing my “new” scale as Quarter would be very misleading - folks would assume Quarter is 1:48 - but that ratio has already got a different, long established number.
So we might be better of with a two letter designation, pulled out of our butt. How about HC as in Holy Crap that’s Big 
- But hold on. HC might be confused with Half C, whatever the F C is.
See how easy it is to F this up ???
Why do we need letters anyway? Just because the smaller scales did it? If you do a little research, you will find that the letters were originally numbers as in Zero, and One. Since typewriters didn’t have Zeros at the time, Zero, became Oh. Then came along that new, small scale, 50% of the Zero scale size - so let’s call it Half Zero, but when we type it on a typewriter it comes out H O.
So the real blame, in my analysis, goes back to the designers of the typewriter saving a couple of keys by not including the numerals 1 and 0 on their keyboard.
Still doesn’t do any better than my email at explaining what F means though
My brain hurts
Jon Radder said:If I only had a brain :P Sigh :(
[i]My brain hurts[/i]
Kevin Strong said:
If I recall, it came out of an ill-fated attempt to ascribe letters to each of the myriad scales we model. #1 - 1:32, A - 1:29, H - 1:24, G - 1:22.5, and F - 1:20.3. The "A" was derived from "Aristo" since they were at the time the principle manufacturer in that scale. The "H" came from "Half inch", the "G," well..., making "F" the logical letter in the progression. Curiously, it's one of those terms that's never really caught on. Even the major manufacturers still refer to the scale as 1:20.3, not "F."Later,
K
K
So why wouldn’t one just state the scale and, if anything other than SG, the gauge. Or would that be too simple? Would be hard to understand, too, since one would have to be capable of basic multiplication and division. Arrrrrgh! GRRRRRRRRRR!
Jon Radder said:
How about if I want to model very narrow, around 1Ft gauge, Industrial on 45mm track....My brain hurts
There are a few nutty guys who are doing 1/10 and 1/8 scale on 45 mm as 18 and 15 inch narrow gauge estate railways. Big stuff!
-Brian
Quote:There was a similar push a while back--probably 10 or so years now--where each scale would be designated "LS##" where the "##" would be the scale. (i.e., 1:29 would be LS29.) By the abundance of such labeling on today's products, you can guess how popular the notion was. That's about as common-sensical an approach as I've ever heard (which is probably what doomed it to failure). Today, we've got a few manufacturers using a "G" in a circle, with the scale sometimes printed somewhere in the circle. Close-ish, but not universal, and at least one manufacturer put one scale in the circle when clearly the product was some other scale. Last I saw, they removed any reference to scale, just using the "G" in the circle. Yeah, that's helpful...
... So why wouldn't one just state the scale and, if anything other than SG, the gauge.
Later,
K
I think we should drop all this alphabetic crap and just go with the scale we run.
Much easier to 'splain it to newbies or observers at shows and open houses.
Scale we don’t need no stinking scale.
When one thinks of ‘F’ scale think aha! a use for those large Bachmann 45-tonners we all have numerous examples of, stuck away out of sight. The mentioned F scale sites show how relatively simple it is to convert to standard gauge. With standard gauge trucks and plans available, F scale could be the ‘new’ fad.
John Bouck said:Yep!
I think we should drop all this alphabetic crap and just go with the scale we run. Much easier to 'splain it to newbies or observers at shows and open houses.
1:22.5 it is! 
John,
Like most of the important things that happen around us it has to do with money or power. In this case NMRA want to ‘have input’ to large scale, maybe hoping to garner new members.
So committees were formed (plural), they studied and studied and came up with recommendations, quickly passed before the participants. We already have G1MRA standards. we run on track and we change scales, wheel widths and diameters, but we’re still on the same track. On that track what scale do you run? What track width does No. 1 gauge represent to you? Meter gauge? 3 ft Narrow Gauge? 2 ft narrow gauge? 42" gauge? 4 8 1/2" pick 1/29th or 1/32.
F? Have no idea what it means, or maybe its a message.
Barry - BBT
…a message of "F"rustration, maybe ?
I just tell ‘em I’m runnin’ 1:20.3 on 45MM track gauge.
Or 1:24 or 1:22.5.
Makes it even more confusing to explain.
So I guess the track gauge is meaningless, it’s the scale of the model that’s important.
John Bouck said:Well that is certainly true for AristoCraft. Their stuff is usually out of gauge and the scale is wrong anyway.
SNIP So I guess the track gauge is meaningless, it's the scale of the model that's important.
But hey!!! it has the WOW!!! factor and mostly runs pretty good.
Gentlemen,
A happy coincidence, when the NMRA guys created the letter designations, was that 1:20.32 scale, or F scale, if converted to metrics, actually works out to 15mm=1 foot. Check out all that "f"ish aliteration!
Dave