Table - Converting Lineal to Board Feet

Nature Man

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Ran across this Table in a very old woodworking magazine. Thought it might be helpful to share. Chuck

Table - Lineal to Board Feet.jpg
 

phinds

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Since the table gives nominal BF, it doesn't seem all that useful. Nominal sizes for dimension lumber are standard but I've never heard of nominal sizes for BF. If I did that table, I produce ACTUAL BF.

Put another way, the table doesn't tell you much about how many BF you're going to get, it tells you how many imaginary BF you WOULD get if the nominal sizes were actual sizes. I don't get how that's useful.
 

Nature Man

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Since the table gives nominal BF, it doesn't seem all that useful. Nominal sizes for dimension lumber are standard but I've never heard of nominal sizes for BF. If I did that table, I produce ACTUAL BF.

Put another way, the table doesn't tell you much about how many BF you're going to get, it tells you how many imaginary BF you WOULD get if the nominal sizes were actual sizes. I don't get how that's useful.
Point well taken. The accompanying article which I did not scan talked about the "actual" sizes. I just thought it was a handy reference chart for ballpark computations. Chuck
 

barry richardson

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Do you think that a "two by four" is actually 2" x 4"
Two by fours aren't sold by the BF though..... Just cross.out the word nominal and the chart works fine. Don't know why they used that word....
 

DLJeffs

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Do you think that a "two by four" is actually 2" x 4"
They used to be but they're shrinking. I think it's a modern day application of the theory of gigantism, miniaturization, and evolution. Lumber survival and propagation of the species obviously favors smaller boards. Hence, a 2X4 that used to be precisely 2 inches by 4 inches is now 1.75 inches by 3.5 inches.
 

2feathers Creative Making

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They used to be but they're shrinking. I think it's a modern day application of the theory of gigantism, miniaturization, and evolution. Lumber survival and propagation of the species obviously favors smaller boards. Hence, a 2X4 that used to be precisely 2 inches by 4 inches is now 1.75 1.5 inches by 3.5 inches.
I haven't seen a 1.75 inch born after 1975
 

phinds

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Two by fours aren't sold by the BF though..... Just cross.out the word nominal and the chart works fine. Don't know why they used that word....
EDIT: OK, forget the below. If they replace the word "nominal" with the word "actual" then yes, the chart works. I still think their INTENT was that they were describing dimensional lumber, but perhaps they don't know what "nominal" means.

No, the chart gives NOMINAL BF, not actual. They used that word because they are describing dimensional lumber (as they specifically state by listed it as "nominal") which is sold by specific sizes that are NOT the sizes listed in the chart, as I'm sure you're well aware. The mythical BF shown in the chart are computed based on the nominal sizes, not the actual sizes.

It's further confused by the fact that they are listed lineal feet, not nominal feet, BUT ... that still doesn't account for the fact that a 1xn, for example, is not really 1" thick, it's 3/4".
 
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phinds

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Hence, a 2X4 that used to be precisely 2 inches by 4 inches is now 1.75 inches by 3.5 inches.
No, it is not. It is 1.5" x 3.5" and has been, as Frank pointed out, for many decades.
 

Nubsnstubs

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They used to be but they're shrinking. I think it's a modern day application of the theory of gigantism, miniaturization, and evolution. Lumber survival and propagation of the species obviously favors smaller boards. Hence, a 2X4 that used to be precisely 2 inches by 4 inches is now 1.75 inches by 3.5 inches.
That size doesn't exist any more when saying 2 x whatever. Today I believe today's Redwood 2x's are 1 3/8" x -1/2". Most other 2x's are at 1 1/2".
All hardwoods I ever purchased are 4/4 at 13/16" thick surfaced, or Blank/Rough at 15/16" thick X the actual width. 5/4 would be 1 3/16" thick for rough and surfaced would be 1 1/16 thick. All quarter sizes are always 1/16 thinner for rough, and surfaced is always 3/16 thinner than the quarter thickness. lately I've gotten some 8/4 Spanish Cedar that was almost 2 1/4 thick, but other hardwoods usually come in at 1 15/16 or 1 13/16 respectively.

Back to the chart. It took awhile to figure out what it is supposed to convey. I had to look for a 6 bdft number to finally get the method. 1 x 6x 12 feet = 6 bdft and then figured it out.

My method never fails. 1' x width x length = then divide by 144. Never fails...... 1 x 6.25 x 66 = 412.5" divide x 144 = 2.8645833 bdft.

I find it really interesting how many people here in the US use metric measurements when posting sizes of things they've done and sometimes how they'll go with length, width and thickness rather thickness, width and length. TWL is how I learned and it's ________ when others list it as LTW....... Jerry (in Tucson)
 
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Mike1950

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So much simpler and more accurate to do the math. Length in inches x width in inches x thickness in inches =X÷144=bd ft
76x 10.25x 1.25=973 cubic inches-ci ÷144=6.76 bd ft
 

DLJeffs

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That size doesn't exist any more when saying 2 x whatever. Today I believe today's Redwood 2x's are 1 3/8" x -1/2". Most other 2x's are at 1 1/2".
All hardwoods I ever purchased are 4/4 at 13/16" thick surfaced, or Blank/Rough at 15/16" thick X the actual width. 5/4 would be 1 3/16" thick for rough and surfaced would be 1 1/16 thick. All quarter sizes are always 1/16 thinner for rough, and surfaced is always 3/16 thinner than the quarter thickness. lately I've gotten some 8/4 Spanish Cedar that was almost 2 1/4 thick, but other hardwoods usually come in at 1 15/16 or 1 13/16 respectively.

Back to the chart. It took awhile to figure out what it is supposed to convey. I had to look for a 6 bdft number to finally get the method. 1 x 6x 12 feet = 6 bdft and then figured it out.

My method never fails. 1' x width x length = then divide by 144. Never fails...... 1 x 6.25 x 66 = 412.5" divide x 144 = 2.8645833 bdft.

I find it really interesting how many people here in the US use metric measurements when posting sizes of things they've done and sometimes how they'll go with length, width and thickness rather thickness, width and length. TWL is how I learned and it's ________ when others list it as LTW....... Jerry (in Tucson)
See, there you go. Boards are just getting smaller and smaller, just like birds and reptiles are getting smaller and smaller from the dinosaurs they came from. It's evolution in action I say.
 
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