Heavy Hardwoods

The Standard Malaysian Name for the timbers of Madhuca utilis, Palaquiumridleyi and P. stellatum (Sapotaceae). Bitis is essentially a Peninsular Malaysian name and in Sabah and Sarawak, the timber is not differentiated from the lighter species and they are sold together as nyatoh. Other vernacular names recorded include belian (Peninsular Malaysia) and seminai (Peninsular Malaysia). The sapwood is yellow-brown to purple-grey-brown and is sharply defined from the heartwood, which is red-brown to purple- or chocolate-red-brown

Also known as Bitis and Nyatoh (Brunei);Mahua,Nyatoh,NyatuhAbang,Seminai and Sulewe (Indonesia); Meze kamzaw (Myanmar), Kajoetorong (Papua New Guinea); Betis and Maloba (Philippines); and Chik-nom, Khanun-nok, Ma Sang and Ma Sarng (Thailand).

DENSITY

The timber is a Heavy Hardwood with a density of 820-1,200 kg/m3 air dry.

NATURAL DURABILITY

The standard graveyard tests conducted at the Forest Research Institute Malaysia (FRIM) have shown that the average service life of M. utilis is 5.5 years under the external exposed conditions and thus, it is classified as durable according to the Malaysian classification (MohdDahlan et al 1987).

PRESERVATIVE TREATMENT

The timber is very difficult to treat with preservatives.

TEXTURE

Texture is moderately fine and even, with straight or shallowly interlocked grain.

STRENGTH PROPERTIES

The timber falls into Strength Group A (Engku, 1988b) or SG 1 (MS 544:Part 2:2001).

Strength Properties of Bitis (M.Utilis)

Test Condition	Modulus of Elasticity (MPa)	Modulus of Rupture (MPa)	Compression parallel to grain (MPa)	Compression perpendicular to grain (MPa)	Shear strength(MPa)
Green	21,900	123	73.6	12.21	11.3
Air dry	23,800	171	90.3	12.48	15.4

MACHINING PROPERTIES

It is slightly difficult to difficult to resaw, easy to slightly difficult to cross-cut. Planing is slightly difficult but the planed surface is smooth.

Sawing and Woodworking Properties of Bitis (M. utilis)

Condition of test	Sawing		Planning		Boring		Turning
	Re Sawing	Cross Cutting	Ease of planing	Quality of finish	Ease of boring	Quality of finish	Ease of Turning	Quality of Finish
Green	Slightly difficult	Easy	Slightly difficult	Smooth	Slightly difficult	Slightly rough, Tendency to split	-	-
Air dry	Difficult	Slightly difficult	Slightly difficult	Smooth	Slightly difficult	Slightly rough	Difficult	Rough

Nailing Property

Nailing property is rated as poor.

Air drying

The timber seasons slowly with moderate end-checking, splitting and surface-checking as the major sources of defects. 38 mm thick boards take approximately 6 months to air dry.

Kiln-Drying

The kiln-drying properties of bitis have not been evaluated. However, based on the physical properties as well as the air drying properties of the timber, it is envisaged that the timber is fairly difficult to dry. A mild schedule (e.g. Schedule B) should therefore be used

Kiln Schedule G

Moisture Content(%)	Temperature (Dry Bulb)		Temperature (Wet Bulb)		Relative Humidity (%)(approx.)
Moisture Content(%)					Relative Humidity (%)(approx.)
Green	105	40.5	101	38.0	85
40	105	40.5	99	37.0	80
30	110	43.5	102	39.0	75
25	115	46.0	105	40.5	70
20	130	54.5	115	46.0	60
15	140	60.0	118	47.5	50

SHRINKAGE

Shrinkage is high. Radial shrinkage averages 2.8% while tangential shrinkage averages 4%.

Uses

The timber is suitable for all forms of heavy construction, bridges, marine construction, piling, posts, beams, joists, rafters, railway sleepers, flooring (heavy traffic), fender supports, poles, mallets, tool handles (impact), laboratory benches, heavy duty furniture, columns (heavy duty), door and window frames and sills, staircase (newels, risers, treads, bullnoses, round ends and winders), vehicle bodies (framework and floor boards), telegraphic and power transmission posts and cross arms.

REFERENCES

Engku Abdul Rahman Chik.1988b. Basic and Grade Stresses for Strength Groups of Malaysian Timbers. Malayan Forest Service Trade Leaflet No.38. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur.13 pp.

Grewal, G.S. 1979b. Kiln-drying Characteristics of Some Malaysian Timbers. Timber Trade Leaflet No. 42. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur. 20 pp.

Lim, S.C. 1989. Malaysian Timbers - Bitis. Timber Trade Leaflet No. 110. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur.6 pp.

Menon, P.K.B. 1986. Uses of Some Malaysian Timbers. Revised by Lim, S.C. Timber Trade Leaflet No. 31. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur.48 pp.

MohdDahlanJantan& Tam Mun Kwong (1987) - Natural Durability of Malaysian Timbers. Timber Trade Leaflet No. 28. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur.

MS 544:Part 2:2001. Code of Practice for the Structural Use of Timber: Permissible Stress Design of Solid Timber.

Wong, T.M. 1982. A Dictionary of Malaysian Timbers. Revised by Lim, S.C. & Chung R.C.K. Malayan Forest Records No. 30. Forest Research Institute Malaysia, Kuala Lumpur. 201 pp.

Heavy Hardwoods - Bitis