How do I estimate the weight of wood?
I'm planning to use torsion hinges for the lid of an oak chest I'm designing. They're rated for the weight of the lid. So before I buy the hardware, how do I estimate the weight of wood?
—Mike Jackson, St. Louis
Calculate weight, Mike, using the formula: density × volume. Well-dried, seasoned oak has of a density of about 3.6 pounds per board foot.
Now find the board footage of your lid by multiplying its length, width, and thickness, and dividing by 144. For example, a lid measuring 3⁄4 ×18×48" contains a volume of 41⁄2 board feet. Multiply that volume by the density, and you find that the oak lid weighs about 16.2 pounds. Use this number along with the manufacturer recommendations to arrive at the weight rating and number of hinges.
- Here are the densities of some other common wood species:
- Pine: 2.5 lbs/board foot
- Cherry: 3 lbs/board foot
- Walnut: 3.3 lbs/board foot
- Hard Maple: 3.75 lbs/board foot
Find the densities of many more woods at woodworkerssource.com. Listed in pounds per cubic feet, you should divide by 12 to discover the weight of a single board foot.