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Is there a standard sequence for writing measurements ?

2K views 20 replies 14 participants last post by  EricFai 
#1 · (Edited by Moderator)
Is there a standard sequence for length height and width ?? It is easy to identify most measurements as they are usually 1"x4"x8'. Not always however. Some CAD and hand drawings leave perception difficult, and some are close such as 4"x3"x6". So what do you do when writing (and reading), is there a standard when you are trying to get your project on paper? I have seen drawings that were all over the place. a 2"x 4" starts with width, or is that just a name? Can it change depend on how it is visually positioned? I guess some are smallest to largest.

Thanks for any insight.
 
#2 ·
I write thickness first, then width, then length. Even in the case of a wood panel wider than it is long I can tell which way the grain is going that way. Sometimes I write thickness last. I'll write W and L often as well, at least once on a piece of paper to remind myself that's the format I'm using.
 
#3 ·
No standard that I'm aware of, consistency is the key.

Most engineering drawings will/would say "all dimensions are in inches, L x W x T/D unless otherwise noted"
Woodworking plans often have the cut lists that would say "3/4" stock, dimensions are length x width". Of course in these lists often you will see every dimension shown with the format "3" L x 4" W x 3/4" T"
That "noted" part means that when a dimension is called out in the drawing (like an angle or arrow pointing to a dado), there would be a notation saying what that dimension represents, i.e. 1/4" wide dado, 1/8" deep).
 
#7 ·
When ordering stuff from china you are lucky to get the 3 main measurements at all. Sometimes looking at stuff online I am thinking there is no way those are the measurements. Then I look at the Q&A and luckily a lot of times people clear up what the measurements actually are. No standard I have ever seen unless dealing with same company.
 
#8 · (Edited by Moderator)
I order 5 8' 2×4s on the materials notation.

Different things have different units.

Rough lumber thickness is in quarters: 4/4, 6/4, 8/4. Board feet is always based on the rough dimension. Widths are usually multiples of 2".

Finished lumber is given as nominals, 2×4, 2×8, etc. But it is known that the actual dims are 1-1/2" x 3-1/2". The nominal dim can be used for bf calculations but the actual dims cannot.

Build drawings have the final dims: 5/8" x 3-3/8" x 17-1/2".

Doors are measured by feet and inches so a 32" wide door is 2-8 (pronounced "two-eight")

A 36" door is 3-0 (three-oh) and this causes endless confusion as folx think "three-oh" means 30" - which it doesn't.

Rough and finish lumber tend to have the length as the first digits because that's how lumber yards sort, by length.

Final dims are generally listed by thickness first, again because this is how stock is sorted.

There are no absolute rules. In England they call a 2×4 a "four by two". Both are correct.

Board feet math is easy in your head if you know the trick. None of this multiply the inches and divide by 144 crap. Memorize this:

  • 2" = 1/6 board feet per lineal foot
  • 3" = 1/4 bf per lf
  • 4" = 1/3 bf per lf
  • 6" = 1/2 bf per lf
  • 8" = 2/3 bf per lf
  • 10" = 5/6 bf per lf
  • 12" = 1 bf per lf

So an 8' 2×4 is 2×1/3 bf/lf or 2/3 bf per 8 lf = 16/3 bf or 5 1/3 bf.

A 8' 1×6 = 8×1/2 bf/lf or 4bf.

A monster beam that is 12' 4×8 = 4×2/3 bf/lf or 8/3 bf/lf x 12 lf = 96/3 bf or 32bf

It seems complicated but in practice you can measure bf and closely estimate costs in your head faster than the counterman can enter it into the calculator.
 
#10 ·
I order 5 8 2×4s on the materials notation.

Different things have different units.

Rough lumber thickness is in quarters: 4/4, 6/4, 8/4. Board feet is always based on the rough dimension.

Finished lumber is given as nominals, 2×4, 2×8, etc. But it is known that the actual dims are 1-1/2" x 3-1/2".

Build drawings have the final dims: 5/8" x 3-3/8" x 17-1/2".

Doors are measured by feet and inches so a 32" wide door is 2-8 (pronounced "two-eight")
A 36" door is 3-0 (three-oh) and this causes endless confusion as folx think "three-oh" means 30" - which it doesn t.

Rough and finish lumber tend to have the length as the first digits because that s how lumber yards sort, by length.

Final dims are generally listed by thickness first, again because this is how stock is sorted.

There are no absolute rules. In England the call a 2×4 a "four by two". Both are correct.

- Madmark2
England???? Like Quigley said "We already run the misfits outta our country. We sent 'em back to England.
 
#13 ·
Good comments. I will to try an remember the board foot (mentioned) lumber, yes standard measurements. As it was mentioned doors are in feet, but try to explain the swing to someone can be difficult for them to understand. When I measure windows it always the width first then the height.
 
#15 ·
No standard that I m aware of, consistency is the key.

- splintergroup
Bruce nailed it. Consistency.

Think it over for a while, you probably have in your mind what you do automatically. Big thing is, make it something that is comfortable, and makes sense to you. Type it out, and make the font huge. Copy it, have it laminated, and hang it on the shop wall. After a while you won't need to look at it, but for a bit it may not immediately come to mind, you have it pre-written down.
 
#17 · (Edited by Moderator)
There is no standard because the industry is so varied. That's like going into a big box store and asking for the standard plumbing pipe to hook up my sink, that animal doesn't exist. In the softwood framing lumber industry, everybody uses 2'x4'x8' so that's T" x W" x L '. Now go order a door from Weyerhaeuser and they are going to list the dimensions W x L x T and it will look something like 2'-8" W x 6'-8" H x 1 3/4" T and somebody in the Hardwood lumber industry might use something entirely different to show their lumber sizes so there is no industry standard because there is too much variety in the industry. * The main thing is, when you are working on your your project and you are trying to get your cut sizes or inventory of goods, whatever it is you are trying to do, keep it simple and convert down to the simplest common item, like all inches. forget about the feet - inch dimensions, like 4'-3", just convert that to 51 inches and save yourself a lot of headache and problems. Use inches and not Feet and Inches together when figuring your cut sizes or product amounts.
 
#19 ·
I write thickness first, then width, then length. Even in the case of a wood panel wider than it is long I can tell which way the grain is going that way. Sometimes I write thickness last. I ll write W and L often as well, at least once on a piece of paper to remind myself that s the format I m using.

- Loren
While I agree with that convention as a default based on construction dimensioning, it makes sense when writing descriptive copy that we add D, W and L after each figure to remain clear. Just sayin'...
 
#20 ·
* The main thing is, when you are working on your your project and you are trying to get your cut sizes or inventory of goods, whatever it is you are trying to do, keep it simple and convert down to the simplest common item, like all inches. forget about the feet - inch dimensions, like 4 -3", just convert that to 51 inches and save yourself a lot of headache and problems. Use inches and not Feet and Inches together when figuring your cut sizes or product amounts.

- Spaceballs
Thanks, Spaceballs. You nailed it exactly like it should be done. T x W x L. I learned that 65 years ago, at 8 years old. As far as doors as windows, take your dims to whoever you're gonna have supply them and they will make the fit.

Engineering and Aviation go by tenths of an inch. That's a little tough when you're working with 16ths and don't have have the proper tape or ruler, but it's doable.

For woodworking, I've found dimensions can vary about 1/64th. The eye can't perceive anything less. ...... Jerry (in Tucson)
 
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