Scientific Name
Upuna borneensis
Trade Name
Upun batu
Family Name
Dipterocarpaceae
Common Names
Balau, Balau penyau, Cangal, Cangal gading, Cangal tanduk, Dusun, Kenyahuk bantuk, Pan yua tanduk, Panyau, Panyau tulang, Penyau, Resak, Tekam, Tekem, Upun, Upun batu
Regions of Distribution
Oceania and S.E. Asia
Countries of Distribution [VIEW MAP]
Brunei, Indonesia, Malaysia
Common Uses
Boat building (general), Bridge construction, Building construction, Building materials, Cabin construction, Construction, Factory construction, Heavy construction, Mine timbers, Wharf construction
Environmental Profile
| Secure in many areas of its range | ||||||||||||
| Extinct, Endangered, Vulnerable, or Rare within its range | ||||||||||||
| Data source is World Conservation Monitoring Center |
Distribution Overview
Described as a lowland forest tree, and is found in Borneo, as well as Sabah, Sarawak, and Brunei.
Heartwood Color
| Red | ||||||||||||
| Black | ||||||||||||
| Brown | ||||||||||||
| Dark brown | ||||||||||||
| Darkens significantly upon exposure |
Lighter when dry
Sapwood Color
| White to yellow | ||||||||||||
| Well defined | ||||||||||||
| Paler than heartwood | ||||||||||||
| Light brown | ||||||||||||
| Different than heartwood | ||||||||||||
| Color not distinct from heartwood |
Grain
| Even | ||||||||||||
| Interlocked | ||||||||||||
| Straight |
| Interlocked | ||||||||||||
| Straight |
Texture
| Medium | ||||||||||||
| Fine | ||||||||||||
| Fine to medium |
Luster
| Medium | ||||||||||||
| Slightly lustrous | ||||||||||||
| Low |
Natural Growth Defects
| Gum/resin exudation | ||||||||||||
| Gum/resin streaks |
Natural Durability
| Moderately durable | ||||||||||||
| Durable | ||||||||||||
| Very durable |
Odor
| No specific smell or taste |
Kiln Schedules
| Drying (speed) is fast |
Drying Defects
| Slight surface checking | ||||||||||||
| Slight end splitting | ||||||||||||
| Checking |
Ease of Drying
Radial: 1.0 to 1.5%
Shrinkage from Green to 15% MC
Tangential: 1.5 to 2.0%
The material dries fairly rapidly, with very little degrade.
Tree Identification
| Bole/stem form is buttressed | ||||||||||||
| Bole/stem form is straight | ||||||||||||
| Bole/stem form is cylindrical |
Tree Size
| Tree height is 20-30 m |
Comments
Twice as hard as Teak, and 50% stonger in other properties except in shock and resistance
Blunting Effect
| Medium effect |
Boring
| Moderately easy | ||||||||||||
| Bores rather roughly |
Cutting Resistance
| Cutting Resistance with green wood is moderate | ||||||||||||
| Cutting Resistance with dry wood is moderate | ||||||||||||
| Cutting Resistance with green wood is difficult | ||||||||||||
| Cutting Resistance with dry wood is difficult | ||||||||||||
| Cutting Resistance with green wood is easy | ||||||||||||
| Cutting Resistance with dry wood is easy |
Planing
| Planes to a smooth surface | ||||||||||||
| Planes to a satisfactory finish | ||||||||||||
| Planes to a satisfactory finish |
It usually planes to a smooth surface but there may be some torn grain on radial surfaces.
Resistance to Impregnation
| Heartwood is highly resistant | ||||||||||||
| Sapwood is extremely resistant |
Response to Hand Tools
| Easy to Work | ||||||||||||
| Moderate working qualities | ||||||||||||
| Easy to machine |
Turning
| High density adversely effects turning |
Presence of gum in the timber are reported to adversely affect most of its machining properties
Strength Properties
| Density (dry weight) = 61-67 lbs/cu.ft | ||||||||||||
| Shrinkage, Tangential = very small | ||||||||||||
| Shrinkage, Radial = very small | ||||||||||||
| Density (dry weight) = 67-75 lbs/cu. ft | ||||||||||||
| Density (dry weight) = 53-60 lbs/cu. ft |
Very high density
Numerical Data
| Item | Green | Dry | English |
| Density | 60 | lbs/ft3 | |
| Specific Gravity | 0.8 | ||
| Weight | 56 | 49 | lbs/ft3 |
| Radial Shrinkage | 2 | % | |
| Tangential Shrinkage | 4 | % | |
| Item | Green | Dry | Metric |
| Density | 961 | kg/m3 | |
| Specific Gravity | 0.8 | ||
| Weight | 897 | 785 | kg/m3 |
| Radial Shrinkage | 2 | % |
References
Andy Poynter. 1993. Personal Communication
Ashton, P.S.,1964,A manual of the Dipterocarp trees of Brunei State,O.U.P. London
Chudnoff, M.,1984,Tropical Timbers of the World,U.S.A. Department of Agriculture, Forest Service, Forest Products,Laboratory, Madison.
Fundter, J.M.,1982,Names for Dipterocarp timbers and trees from Asia,Pudoc, Wageningen, Netherlands
Meijer, W., Wood, G.H.S.,1964,Dipterocarps of Sabah (North Borneo,Sabah Forest Department, Forest Record No.5
Moore, K.M.,1972,Observations on some Australian forest insects: 26 Some insects attacking,three important tree species (Eucalyptus grandis, Eucalyptus pilularis and,Eucalyptus saligna,Australian Zoologist 17(1) pp30-9
Sarawak Forestry Department,1953,Trees and Timbers of Sarawak and Brunei – Leaflet No. 9 Family,Dipterocarpaceae,Forest Department of Sarawak
Thomas, A.V.,1953,The timber of Upun Batu (Upuna borneensis,Malaysian Forester 16(3, 163-5
WCMC. 1992. Conservation Status Listing – Trees and Timbers of the World. World Conservation Monitoring Center-Plants Programme, Cambridge, CB3 ODL, United Kingdom.