Color: Heartwood is yellow-brown when freshly cut, turning dark-brown to almost black with alternate layers of light and dark. Sapwood is yellowish-white and clearly demarcated from heartwood.
Grain: Straight when quartersawn; coarse texture.
Variations Within Species And Grades: Moderate variations in color.
Hardness/Janka: Janka: 1630; (26% harder than Northern red oak).
Dimensional Stability: Excellent (5.8; 33% more stable than red oak). However, actual installations have demonstrated significant movement in use.
Sawing/Machining: Difficult due to rapid dulling of tools; carbide tooling recommended.
Nailing: No known problems.
Sanding: Difficult. Scratches are easily seen each sanding. Suggested Sequence: First Cut: 36 or 40 Second Cu: 50 or 60 Third Cut: 80 Hard Plate: 100 Screen: 80, then 100
Finishing: Test all products before using them on the actual floor. Oil-modified finishes may not dry if standard procedures are followed. Moisture-cure urethane, conversion varnish, or water base finishes are generally more successful.
Comments: Dermatological and respiratory allergic potential.