Wood species
Spanish cedar wood
Spanish cedar is a hardwood (Cedrela spp.). At 12% moisture content it has a Janka hardness of 600 lbf (2,669 N) and it weighs about 31 lb/ft³ (489 kg/m³), 2.5 lb (1.16 kg) per board foot.
Also called: Spanish-cedar, cedro.
Key numbers
- Janka hardness, 12% MC
- 600 lbf (2,669 N)
- Green: 550 lbf (2,447 N)
- Weight at 12% MC
- 31 lb/ft³ (489 kg/m³)
- 2.5 lb per board foot
- Specific gravity (oven-dry weight)
- 0.41 on green volume
- Shrinkage, green to oven-dry
- 6.3% tangential
- Radial 4.2%, volumetric 10.3%
One source: USDA Forest Products Laboratory, collected from the world literature (its Tables 5-5 and 4-4)
Why: From the USDA Wood Handbook, which collected these values from the world literature; Spanish cedar's density is worked from its specific gravity with the Handbook's own equations.
How much Spanish cedar moves
A 12 in wide flatsawn board of spanish-cedar that goes from 6% to 12% moisture content swells about 0.16 in (about 5/32 in, 4 mm). Quartersawn, the same board moves about 0.1 in (about 3/32 in, 2.6 mm). Flatsawn faces move 1.5 times as much as quartersawn ones, because the wood shrinks 6.3% around the growth rings but only 4.2% across them.
Worked from the Wood Handbook's shrinkage values (Table 4-4) with its Eq. 13-4; the Handbook gives no movement coefficients for imported woods. Individual boards vary: the Handbook gives shrinkage a coefficient of variation of about 15% (p. 4-11).
Color, grain and working
- Color
- Light to dark reddish brown heartwood; pinkish to white sapwood.
- Grain and texture
- Ring-porous; texture from rather fine and uniform to coarse and uneven; grain not interlocked. The heartwood has a distinctive smell.
- Working and character
- Not high in strength, but otherwise much like American mahogany except softer. Dries easily, resists decay, works and glues well.
- Uses
- Millwork, cabinets, fine furniture, boat building, cigar boxes and humidors, and decorative and utility plywood.
A hardwood despite its name. The Handbook reports that some Cedrela species are listed as endangered by the IUCN and the genus is in CITES Appendix III.
Adapted in our own words from the Wood Handbook, Chapter 2, p. 2-37.
Strength
Bending strength is the modulus of rupture (MOR); stiffness is the modulus of elasticity (MOE). Values for spanish-cedar from Wood Handbook Table 5-5b (p. 5-25), which the Handbook says were collected from the world literature, on clear, straight-grained specimens. Knots and cross grain make lumber weaker than these clear samples (Handbook Chapter 5).
| Property | Green | 12% MC |
|---|---|---|
| Bending strength (MOR) | 7,500 psi (52 MPa) | 11,500 psi (79 MPa) |
| Stiffness (MOE) | 1,310,000 psi (9 GPa) | 1,440,000 psi (9.9 GPa) |
| Crushing strength (compression parallel to grain) | 3,370 psi (23 MPa) | 6,210 psi (43 MPa) |
| Shear parallel to grain | 990 psi (7 MPa) | 1,100 psi (8 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
Why these numbers
Why these numbers?
The situation
The Wood Handbook prints 600 lbf of side hardness at 12% moisture content for spanish-cedar, a value it says was collected from the world literature (Table 5-5b, p. 5-25).
One source: USDA Forest Products Laboratory, collected from the world literature (its Tables 5-5 and 4-4) , 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, collected from the world literature (its Tables 5-5 and 4-4) , sources [1]
So
The Handbook gives only the green specific gravity (0.41) for spanish-cedar, so it is moved to 12% with the volumetric shrinkage of 10.3% (Eqs. 4-9 and 4-11), then multiplied by water's density and 1.12 (Eq. 4-14).
Arithmetic: exact by definition , sources [1]
The number
About 31 lb/ft³, or 2.5 lb per board foot (1/12 ft³), at 12% moisture content.
Arithmetic: exact by definition
Sources