Wood species
Pitch pine wood
Pitch pine is a softwood (Pinus rigida). It weighs about 36 lb/ft³ (582 kg/m³), 3 lb (1.37 kg) per board foot.
Also called: Pinus rigida.
Key numbers
- Janka hardness, 12% MC
- Not measured
- Weight at 12% MC
- 36 lb/ft³ (582 kg/m³)
- 3 lb per board foot
- Specific gravity (oven-dry weight)
- 0.52 at 12% MC volume
- 0.47 on green volume
- Shrinkage, green to oven-dry
- 7.1% tangential
- Radial 4.0%, volumetric 10.9%
One source: USDA Forest Products Laboratory, the authority for species properties it measured
Why: Measured by the USDA Forest Products Laboratory; pitch pine's density is worked from its specific gravity with the Handbook's own equation.
How much pitch pine moves
A 12 in wide flatsawn board of pitch pine that goes from 6% to 12% moisture content swells about 0.18 in (about 3/16 in, 4.5 mm). Quartersawn, the same board moves about 0.13 in (about 1/8 in, 3.2 mm). Flatsawn faces move 1.8 times as much as quartersawn ones, because the wood shrinks 7.1% around the growth rings but only 4.0% across them.
Worked with the Wood Handbook's dimensional change coefficients for pitch pine (Table 13-5: 0.00248 tangential, 0.00176 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
- Brownish red or dark orange, resinous heartwood; wide, light yellow sapwood.
- Working and character
- Moderately heavy to heavy, moderately strong, stiff and hard, and moderately high in shock resistance; shrinkage ranges from moderately low to moderately high.
- Uses
- General construction, lumber, posts, poles, fuel and pulpwood; graded as a minor Southern Pine species.
Adapted in our own words from the Wood Handbook, Chapter 2, p. 2-14.
Strength
Bending strength is the modulus of rupture (MOR); stiffness is the modulus of elasticity (MOE). Clear, straight-grained samples of pitch pine 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) | 6,800 psi (47 MPa) | 10,800 psi (74 MPa) |
| Stiffness (MOE) | 1,200,000 psi (8.3 GPa) | 1,430,000 psi (9.9 GPa) |
| Crushing strength (compression parallel to grain) | 2,950 psi (20 MPa) | 5,940 psi (41 MPa) |
| Compression perpendicular to grain | 360 psi (2 MPa) | 820 psi (6 MPa) |
| Shear parallel to grain | 860 psi (6 MPa) | 1,360 psi (9 MPa) |
| Tension perpendicular to grain | — | — |
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 pitch pine
Work it out for your project
- Rank woods for ground contact with the species picker
Weigh pitch pine against other woods on hardness, weight, movement and color, every figure from the Wood Handbook.
Why these numbers
Why these numbers?
The situation
The Wood Handbook prints no side hardness for pitch pine (Table 5-3b shows "—"), so none is given here.
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 × 0.52 × 1.12.
Arithmetic: exact by definition , sources [1]
The number
About 36 lb/ft³, or 3 lb per board foot (1/12 ft³), at 12% moisture content.
Arithmetic: exact by definition
Sources