Board foot
| Board-Foot Measure | |
|---|---|
| Unit of | Volume |
| Symbol | FBM |
| Unit conversions | |
| 1 FBM in ... | ... is equal to ... |
| SI base units | ≈0.002359737 m3 |
| US Customary | 1⁄12 ft3 |
The board-foot is a specialized unit of measure for the volume of lumber in the United States and Canada. It is the volume of a one-foot length of a board one foot wide and one inch thick.
Board-foot can be abbreviated FBM (for "foot, board measure"), BDFT, or BF. Thousand board-feet can be abbreviated as MFBM, MBFT, or MBF. Similarly, million board-feet can be abbreviated as MMFBM, MMBFT, or MMBF.
| FBM multiples |
|---|
| fbm= board-foot |
| mfbm=thousand board-feet |
| mmfbm=million board-feet |
In Australia and New Zealand the term super foot or superficial foot was used to mean the same.[1][2][3]
One board-foot equals:
- 1 ft × 1 ft × 1 in
- 12 in × 12 in × 1 in
- 30.48 cm × 30.48 cm × 2.54 cm
- 144 in3
- 1⁄12 ft3
- 2360 cm3
- 2.360 liters
- 0.002360 cubic meters or steres
- 1/1980 Petrograd Standard of board
Board foot is the unit of measure for rough lumber (before drying and planing with no adjustments) or planed/surfaced lumber. An example of planed lumber is softwood 2 × 4 lumber one would buy at a large lumber retailer. The 2 × 4 is actually only 1 1⁄2 in × 3 1⁄2 in (38 mm × 89 mm) but the dimensions for the lumber when purchased wholesale could still be represented as full 2 × 4 lumber, although the "standard" can vary between vendors. This means that nominal lumber includes air space around the physical board when calculating board feet in some situations, while the true measurement of "board feet" should be limited to the actual dimensions of the board.
For planed lumber, board-feet refer to the nominal thickness and width of lumber, calculated in principle on its size before drying and planing. Actual length is used.
See dimensional lumber for a full discussion of the relationship of actual and nominal dimensions. Briefly, for softwoods, to convert nominal to actual, subtract 1⁄4 inch for dimensions under 2 inches (51 mm); subtract 1⁄2 inch for dimensions under 8 inches (203 mm); and subtract 3⁄4 inch for larger measurements. The system is more complicated for hardwoods.
An Essex table is a tabulation of the number of board feet in lumber of varying dimensions.[4]
See also
References
- ↑ Rowlett, Russ. "How Many? A Dictionary of Units of Measurement". Retrieved 2007-01-30.
- ↑ Burger, Les. "Cutting Timber on Springbrook in 1935". Archived from the original on September 17, 2007. Retrieved 2007-11-06.
- ↑ Holgate, Alan. "The Bendigo Monier Arch Bridges.". Retrieved 2007-11-06.
- ↑ "Essex table | Define Essex table at Dictionary.com". Dictionary.reference.com. Retrieved 2010-09-26.