Ulin is found primarily in Kalimantan (Borneo), Sumatra, and parts of Sulawesi. It grows in lowland tropical rainforests. Ulin is used for heavy-duty construction, outdoor applications, flooring, bridges, railway sleepers, and boat building.
Scientific Name: Eusideroxylon zwageri
Density : Approximately 850-1,000 kg/m³ at 12% moisture content
Color : Dark brown to reddish-brown; darkens with age
Grain : Straight to interlocked
Texture : Coarse
Durability : Highly durable; very resistant to decay, insects, and termites
Workability : Difficult to work with due to its density; requires pre-drilling for nailing and can dull cutting tools; takes stains and finishes well
Growth Time : Typically harvested after 40 to 60 years of growth