Wood species
Noble fir wood
Noble fir is a softwood (Abies procera). At 12% moisture content it has a Janka hardness of 410 lbf (1,824 N) and it weighs about 27 lb/ft³ (437 kg/m³), 2.3 lb (1.03 kg) per board foot.
Also called: Abies procera.
Key numbers
- Janka hardness, 12% MC
- 410 lbf (1,824 N)
- Green: 290 lbf (1,290 N)
- Weight at 12% MC
- 27 lb/ft³ (437 kg/m³)
- 2.3 lb per board foot
- Specific gravity (oven-dry weight)
- 0.39 at 12% MC volume
- 0.37 on green volume
- Shrinkage, green to oven-dry
- 8.3% tangential
- Radial 4.3%, volumetric 12.4%
One source: USDA Forest Products Laboratory, the authority for species properties it measured
Why: Measured by the USDA Forest Products Laboratory; noble fir's density is worked from its specific gravity with the Handbook's own equation.
How much noble fir moves
A 12 in wide flatsawn board of noble fir that goes from 6% to 12% moisture content swells about 0.21 in (about 7/32 in, 5.4 mm). Quartersawn, the same board moves about 0.11 in (about 3/32 in, 2.7 mm). Flatsawn faces move 1.9 times as much as quartersawn ones, because the wood shrinks 8.3% around the growth rings but only 4.3% across them.
Worked with the Wood Handbook's dimensional change coefficients for noble fir (Table 13-5: 0.00293 tangential, 0.00148 radial per 1% change in moisture content), which hold between 6% and 14%. Individual boards vary: the Handbook gives shrinkage a coefficient of variation of about 15% (p. 4-11).
Color, grain and working
- Color
- Creamy white to pale brown, like the other true firs.
- Working and character
- A western true fir: light in weight, somewhat stronger than balsam fir, with low to moderately high shrinkage.
- Uses
- High-grade noble fir goes into interior woodwork, molding, siding, and sash and door stock; the best has been used for aircraft, and some for venetian blinds and ladder rails.
The Handbook says the true firs cannot be told apart by their wood alone; western true firs are marketed as white fir.
Adapted in our own words from the Wood Handbook, Chapter 2, p. 2-12.
Strength
Bending strength is the modulus of rupture (MOR); stiffness is the modulus of elasticity (MOE). Clear, straight-grained samples of noble fir tested by the Forest Products Laboratory (Wood Handbook Table 5-3b). Knots and cross grain make lumber weaker than these clear samples (Handbook Chapter 5).
| Property | Green | 12% MC |
|---|---|---|
| Bending strength (MOR) | 6,200 psi (43 MPa) | 10,700 psi (74 MPa) |
| Stiffness (MOE) | 1,380,000 psi (9.5 GPa) | 1,720,000 psi (11.9 GPa) |
| Crushing strength (compression parallel to grain) | 3,010 psi (21 MPa) | 6,100 psi (42 MPa) |
| Compression perpendicular to grain | 270 psi (2 MPa) | 520 psi (4 MPa) |
| Shear parallel to grain | 800 psi (6 MPa) | 1,050 psi (7 MPa) |
| Tension perpendicular to grain | 230 psi (2 MPa) | 220 psi (2 MPa) |
A dash means the Handbook prints no value; none is filled in.
Dust and health
- Wood dust is classed as carcinogenic to humans (Group 1) by the International Agency for Research on Cancer, chiefly for cancers of the nose and sinuses.
- NIOSH recommends keeping wood dust exposure to 1 mg/m³ of total dust, as quoted in OSHA's sawmill guidance.
This is what the named authorities publish, not medical advice.
Compare with
Buying and finishing noble fir
Work it out for your project
- Rank woods for cabinets and trim with the species picker
Weigh noble fir against other woods on hardness, weight, movement and color, every figure from the Wood Handbook.
- Plan a finish for cabinets in noble fir
The finishes whose makers name that use, and a dated coat schedule from each product’s own sheet.
Why these numbers
Why these numbers?
The situation
The USDA Forest Products Laboratory measured noble fir at 410 lbf of side hardness at 12% moisture content, on clear, straight-grained samples (Wood Handbook Table 5-3b).
One source: USDA Forest Products Laboratory, the authority for species properties it measured , sources [1]
What that means
Side hardness (Janka) is the load needed to press a 0.444 in (11.28 mm) steel ball halfway into the wood across the grain; a higher number dents less (Handbook p. 5-5).
One source: USDA Forest Products Laboratory, the authority for species properties it measured , sources [1]
So
Density at 12% is water's density × specific gravity × (1 + 0.12) (Handbook Eq. 4-14): 62.43 × 0.39 × 1.12.
Arithmetic: exact by definition , sources [1]
The number
About 27 lb/ft³, or 2.3 lb per board foot (1/12 ft³), at 12% moisture content.
Arithmetic: exact by definition
Sources