The Wood Picker
A wood selection tool
Use the Wood Picker to identify candidate woods for a woodworking
project. Just enter the desired criteria for each property of interest,
click Submit, and a list of matching woods will be displayed. The output
includes properties of woods that are exact matches as well as
properties of all other woods, ranked from highest to lowest relevance.
To display properties of all woods, select "omit" by
clicking Reset button.
If "show" is unchecked for a particular property, it will not be
displayed in the output results.
There are currently 128 woods and wood groups in the database.
Description of Wood Properties
Weight: Average ovendry weight. Rankings based
on pounds per cubic foot: < 33 = low (light); 33 to 43 = medium
(moderately heavy); > 43 = high (heavy).
Hardness: Side hardness or ability to resist
compression perpendicular to the grain. Rankings based on fiber
stress at proportional limit in pounds per square inch (psi): < 850 =
low (dents easily); 850 to 1250 = medium (moderate hardness); > 1250 =
high (hard).
Stiffness: Elasticity or ability to resist bending
stress. Rankings based on modulus of elasticity in million psi: < 1.25 =
low (bends easily); 1.25 to 1.65 = medium (moderate stiffness); > 1.65 =
high (stiff).
Bending Strength: Maximum bending stress before
failure occurs. Rankings based on modulus of rupture in psi: < 11000 =
low (weak); 11000 to 14000 = medium (moderately strong); > 14000 = high
(strong).
Shock Resistance: Impact strength or toughness.
Measured by dropping a 50 pound hammer on a board supported on both ends
at successively increasing heights until complete rupture occurs.
Rankings based on max height of hammer in inches: < 30 = low; 30 to 55 =
medium; > 55 = high.
Decay Resistance: Ability to resist deterioration
due to decay fungi. Rankings based on relative decay resistance: low
(little resistance); medium (some resistance); high (very decay
resistant). Heartwood is generally more decay resistant than sapwood.
Stability: Dimensional stability in service
associated with changes in humidity levels. Rankings based on average
seasonal movement of kiln dried wood: low (not stable); medium (fairly
stable); high (very stable).
Working ease: How easily the wood
is worked. These rankings are somewhat more subjective than those for
the other criteria but they take into account things such as blunting
effects on cutting edges and how easily the wood splinters, chips, and
burns. Rankings: low (works with difficulty); medium (works fairly
easily); high (works easily).
Type: Hardwood (angiosperm) or softwood
(gymnosperm). Softwoods are typically less dense than hardwoods,
making them easier to cut and nail without pre-drilling. Pines, firs,
hemlocks, cedars, and spruces are all softwoods.
Location: Geographic region where each tree grows.
Note that the region "Australia-Oceania" includes Australia and
surrounding islands such as New Zealand, New Guinea, Guam, Fiji, the
Marshall Islands, Micronesia, and Tasmania. "Asia" includes mainland
Asia as well as Indonesia, Malaysia, Japan, and other southeast Asia
islands.
Scoring
A score is computed for each wood based on how well it's properties
match the selected criteria. These scores are on a 100 percent
scale. For example, suppose you choose to screen woods based solely on
hardness and you specify a hardness criteria of "high". All woods with a
hardness ranking of high will score a 100 percent, those with a ranking
of medium will score an 80, and those with a ranking of low will score a
60. If you choose a hardness criteria of "medium", woods with a
hardness of medium will score a 100 and woods with a hardness of low or
high will score an 80. In other words, an exact match is worth 100, a
close match (off by one unit) is worth 80, and a poor match (off by two
units) is worth 60. All wood properties with three choices (low, med,
high) are scored this way.
For wood type and location, an exact match scores 100 and an inexact
match scores 60. For example, if you select "softwood" for the wood type
criteria, all softwoods will score 100 and hardwoods will score 60. When
multiple wood properties are selected for screening, the individual
scores for each property will be averaged together to form a composite
score that is still on a 100 percent scale. Woods with equal scores are
arranged alphabetically within their group.
mild disclaimer: The scores are useful for seeing
how woods compare to each other but they do have their limitations. For
instance, in the real world, Lignum vitae far outranks perhaps all other
woods in the categories of weight and hardness, but with the
low-med-high ranking scheme used here, it would score the same as red
oak. Further, there is a certain subjectivity involved in assigning
rankings to properties such as working ease and decay resistance and
also in determining the cutoff point between, say, a "heavy" wood and a
"moderately heavy" wood.
Bottom line - use the scores as a guide but don't get too hung up on
them. Also, the greater the number of screening criteria, the more
realistic the scores.
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