Botanical Name: Shorea spp.
Also known as Yellow Balau, Balau Kuning, Selagan Batu
Native to Malaysia, Indonesia and the Philippines, Bangkirai is a dense hardwood used mainly for heavy construction.
The heartwood of Bangkirai is yellow to brown, which is distinct from the paler sapwood. Its moderately fine and even texture presents and interlocked grain, which produces a stripe figure on the radial surface. Bangkirai is also susceptible to pinhole borer damage.
In relation to its density, Bangkirai is relatively easy to work. It does not contain sillica, however resin pockets may be present, meaning resin can build up on cutting equipment. Pre-drilling is advisable when nailing. Bangkirai can be painted, stained and polished but is not suitable for steam bending.
| Density | 900kg/m3 seasoned |
| Strength Groups | S3 unseasoned; SD2 seasoned |
| Stress Grades | F8, F11, F14, F17 (unseasoned), F14, F17, F22, F27 (seasoned) |
| Joint Groups | J2 unseasoned; JD2 seasoned |
| Shrinkage to 12% MC | 6.5-8.0% (tangential); 4.0-5.0% (radial) |
| Durability Above-ground | Class 1 – life expectancy over 40+ years |
| Durability In-ground | Class 2 – life expectancy 15-25 years |
| Lyctine Suceptibility | Untreated sapwood susceptible to lyctid borer attack |
| Termite Resistance | Not Resistant |
| Machining | Machines reasonably well to a smooth surface. However, some of the lower density species may give a woolly cut if sharp tools are not used. |
| Fixing | No difficulty has been experienced with the use of standard fittings and fastenings. |
| Gluing | Can be satisfactorily bonded using standard procedures. |
| Finishing | Can be painted, stained or polished. However, due to its open grain timber surfaces may need to be filled before finishing. |
| Bush Fire Resistance | Bal 12.5 and 19 AS3959 |
