Wood species
Meranti wood
Meranti is a hardwood; this page covers the meranti groups (shorea), led by dark red meranti (Shorea spp.). At 12% moisture content it has a Janka hardness of 780 lbf (3,470 N) and it weighs about 35 lb/ft³ (559 kg/m³), 2.9 lb (1.32 kg) per board foot.
Names and species on this page: lauan, Philippine mahogany, seraya.
Key numbers
- Janka hardness, 12% MC
- 780 lbf (3,470 N)
- Green: 700 lbf (3,114 N)
- Weight at 12% MC
- 35 lb/ft³ (559 kg/m³)
- 2.9 lb per board foot
- Specific gravity (oven-dry weight)
- 0.46 on green volume
- Shrinkage, green to oven-dry
- 7.9% tangential
- Radial 3.8%, volumetric 13.1%
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; meranti's density is worked from its specific gravity with the Handbook's own equations.
How much meranti moves
A 12 in wide flatsawn board of dark red meranti that goes from 6% to 12% moisture content swells about 0.2 in (about 3/16 in, 5.1 mm). Quartersawn, the same board moves about 0.09 in (about 3/32 in, 2.4 mm). Flatsawn faces move 2.1 times as much as quartersawn ones, because the wood shrinks 7.9% around the growth rings but only 3.8% across them.
Worked from the Wood Handbook's shrinkage values (Table 4-4, row "Lauan, dark red") 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
- Dark red meranti is dark brown to deep red; light red is anything from almost white to dark red; white is whitish turning light yellow-brown; yellow is light yellow or yellow-brown.
- Grain and texture
- Coarser than mahogany, usually interlocked, with resin canals in long lines on the end grain.
- Working and character
- Strength and shrinkage compare with northern red oak. All machine easily except white meranti, whose silica dulls cutters. Dark red meranti is moderately durable; the others are not durable outdoors.
- Uses
- Sold widely as lauan or “Philippine mahogany”: plywood, millwork and furniture.
The Handbook reports that many Shorea species are rated endangered or critically endangered by the IUCN.
Adapted in our own words from the Wood Handbook, Chapter 2, p. 2-30.
Strength
Bending strength is the modulus of rupture (MOR); stiffness is the modulus of elasticity (MOE). Values for dark red meranti 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) | 9,400 psi (65 MPa) | 12,700 psi (88 MPa) |
| Stiffness (MOE) | 1,500,000 psi (10.3 GPa) | 1,770,000 psi (12.2 GPa) |
| Crushing strength (compression parallel to grain) | 4,720 psi (33 MPa) | 7,360 psi (51 MPa) |
| Shear parallel to grain | 1,110 psi (8 MPa) | 1,450 psi (10 MPa) |
A dash means the Handbook prints no value; none is filled in.
The meranti groups (shorea)
The Handbook tests each species separately; they are sold together as meranti. Across the 3 species measured, Janka hardness at 12% runs from 460 to 780 lbf.
| Species | Janka, 12% MC | Weight, 12% MC | Tangential shrinkage |
|---|---|---|---|
| Dark red merantiShorea spp. | 780 lbf | 35 lb/ft³ | 7.9% (listed as dark red lauan) |
| Light red merantiShorea spp. | 460 lbf | 26 lb/ft³ | 8.5% (listed as light red and red lauan) |
| White merantiShorea spp. | 1,140 lbf (at 15%) | 40 lb/ft³ | 6.6% |
| Yellow merantiShorea spp. | 770 lbf | 34 lb/ft³ | 8.0% |
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 780 lbf of side hardness at 12% moisture content for dark red meranti, 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 (0.46) for dark red meranti, so it is moved to 12% with the volumetric shrinkage of 13.1% (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 35 lb/ft³, or 2.9 lb per board foot (1/12 ft³), at 12% moisture content.
Arithmetic: exact by definition
Sources