What's the difference between a plank and a board?

Question

Okay, I know it's the thickness, but what's the cut-off?

Answer 1

I think at one time a plank was made by splitting (using wedges) two sides off from a log leaving a flatish center section. This would then be planed down to the required thickness and smoothness.
Therefore you could really only get one plank out of a log.

A board was/is made by sawing and is a faster more efficient process resulting in more usable wood per log.

In more recent times I think plank has come to mean a board that is 2" or more in thickness.

At some point you start to get beams but I have no idea what the definition would be, I would expect it to have something to do with the ratio of thickness to width.

Here would be a good forum to ask.
http://www.woodweb.com/cgi-bin/forums/sawdry.pl
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Andre' B.

Answer 2

I understand the difference to be: A board has been planed and a plank has not. Planning does take away some thickness but more important is the fact that it (Planning) brings the wood closer to Square. Or Trues up one edge.

Answer 3

This is nit-picky, but a beam refers to how the item is used. A beam is a member that carries weight over a span or on a cantilever.

I agree that the distinction used to be whether split or sawn---see previous answers.

Nowadays, any piece of wood two inches or greater nominal is considered a plank---note a 2x12 is 1-1/2 inches thick, a plank.

Answer 4

The difference between a plank and a board? The name!

Answer 5

Aye matey, I have walked the plank, but would be thrown out of the pirates union if I "Walked the board"

Answer 6

a plank is less than 100 mm

board is greater than

Answer 7

the plamk has a section that gives a bigger magnitude for moment of inertia where people need to walk on