Variations within species and grades: Moderate to high color variation.
Hardness (Janka): 2350; 82% harder than Northern red oak.
Dimensional Stability: Average (change coefficient .00300; 19% more stable than red oak). However, actual installations have demonstrated significant movement in use.
Durability: Dense and very strong.
Sawing/Machining: Sawing is difficult due to high density; requires frequent resharpening of tools. Planing is difficult due to interlocked grain. Can be machined to a smooth surface. Carbide tooling recommended.
Sanding: Sands well.
Nailing: Good holding ability, but due to hardness may require adjustment of angle of penetration and/or height.
Finishing: No known problems.
Comments: Light-sensitive; darkens rapidly upon exposure to sunlight.
Information is from The National Wood Flooring Association
"Wood Species Used in Wood Flooring"