Curmaru Appearance Color: At first, red-brown or purple-brown with light yellow-brown or purple streaks, after exposure uniform light brown or yellow-brown. Grain: Fine texture, interlocked, waxy or oily feel. Variations Within Species And Grades: Dramatic shading that mellows as the floors matures. Properties Hardness/Janka: 3540; 174% harder than Northern red oak Dimensional Stability: Average (7.6; 7% more stable than red oak). Durability: Workability Sawing/Machining: Works well, but is very hard – use carbide blades and bits. 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 Nailing: Predrilling and hand-nailing is preferred. 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: Has been known to cause contact dermatitis. Availability Moderately available. Source: National Wood Flooring Association