Northern Red Oak

Quercus rubra · Hardwood · North America

Janka 1,290 lbf≈39 lb/ft³ dried (est.)Not durable

Properties

Janka hardness	1,290 lbf (5,738 N)
Average dried weight (est.)	39 lb/ft³ (630 kg/m³)
Specific gravity	0.63
Modulus of rupture	14,300 psi (98.6 MPa)
Modulus of elasticity	1.82 million psi (12.55 GPa)
Crushing strength	6,760 psi (46.6 MPa)
Shrinkage — radial	4.0%
Shrinkage — tangential	8.6%
Shrinkage — volumetric	13.7%
Shrinkage T/R ratio	2.1

Values at 12% moisture content, clear-wood averages. Source: USDA Forest Products Laboratory, Wood Handbook FPL-GTR-282 (2021), Table 5–3b p. 5–10; shrinkage Table 4–3 p. 4–8.

Northern red oak is one of the principal species of the red oak group, a heavy hardwood (specific gravity 0.63, Janka hardness 1,290 lbf). Red oak lumber cannot be separated by species, so it is sold as a group and remanufactured into flooring, furniture, and general millwork.

Appearance & grain

The sapwood is nearly white and about 2 to 5 cm wide. The heartwood is brown with a tinge of red. The pores stand open, with tyloses generally absent, which is why red oak is unsuitable for tight cooperage unless the barrels are lined.

Durability

Not durable untreated: the Handbook states that red oak railroad ties, mine timbers, and fence posts require preservative treatment to give satisfactory service.

Workability

Red oak is heavy and shrinks fairly heavily on drying, so seasoning needs care. Because the pores are open, the wood accepts preservative treatment, which the Handbook says its ties, mine timbers, and fence posts require for satisfactory service.