Machang Wood

INTRODUCTION

The Standard Malaysian Name for the wood of Mangifera spp. (Anacardiaceae). Many vernacular names for the species of this genus have been recorded and they include asam (Sabah) with various epithets, bachang (Peninsular Malaysia and Sarawak), lanjut (Peninsular Malaysia), figured asam (Sabah), machang api (Peninsular Malaysia), machang hutan (Peninsular Malaysia), mangga (Peninsular Malaysia), mempelam (Peninsular Malaysia), pauh (Peninsular Malaysia), rawa (Peninsular Malaysia) and other localised names too numerous to list here. Major forest species of Mangifera include M. applanata, M. caesa, M. foetida, M. griffithii, M. indica, M. longipetiolata, M. laurina, M. odorata, M. pajang, M. parviflora, M. quadrifida and M. torquenda. The sapwood is not clearly defined from the heartwood, which is light pink-brown to light brown. In many trees, a streaky corewood is produced, where the wood is dark brown interspersed with streaks of blacks. This figured material is usually with a natural sheen.

Also known as Pacific walnut (Australia); Machang (Brunei); Svay prey (Cambodia); Mangga and Mango (India); Mangga hutan and Membacang (Indonesia); Thayet (Myanmar); Magga and Mango (Pakistan); Malapaho, Paho and Pahutan (Philippines); Ailai and Asai (Soloman Islands); Estamba (Sri Lanka); Ma Muang Pa and Mamuang (Thailand); and Xoan tia (Vietnam).

DENSITY

The wood is a Light Hardwood with a density of 545-610 kg/m³ air dry.

NATURAL DURABILITY

The wood is moderately durable to non-durable under exposed conditions. Under graveyard test conditions, untreated specimens of M. foetida (50 mm x 50 mm x 600 mm) lasted only up to two years. The wood is subjected to subterranean termite and fungal attacks. Treated specimens of the same size and species were planted in the graveyard test site and after 22 years, 60% of the specimens have been destroyed (Tam, 1982).

PRESERVATIVE TREATMENT

This wood is classified as very easy to average to treat with preservatives.

TEXTURE

Texture is moderately fine and even with straight to interlocked grain.

STRENGTH PROPERTIES

The wood falls into Strength Group C (Engku, 1988b) or SG 6 (MS 544:Part 2:2001).

Strength Properties of Machang 

Species	Test Condition	Modulus of Elasticity(MPa)	Modulus of Rupture(MPa)	Compression parallel to grain (MPa)	Compression perpendicular to grain (MPa)	Shear strength(MPa)
M. indica	Green	6,700	44	21.8	–	9.2
	Air dry	7,500	57	32.1	–	12.2
M. foetida	Green	12,800	68	36.3	4.83	9.0
	Air dry	14,300	90	48.2	6.14	13.1

MACHINING PROPERTIES

It is slightly difficult to resaw when green but is easy when air dry. Planing is easy but the surface produced is only moderately smooth with grain pick-up on the radial side.

Machining Properties of Machang 

Species	Test Condition	Sawing		Planing		Boring		Turning
		Re-sawing	Cross Cutting	Ease of planing	Quality of finish	Ease of boring	Quality of finish	Ease of turning	Quality of finish
M. foetida	Green	easy to difficult	easy	easy	tangential: smooth; radial: rough	easy	rough to smooth	–	–
	Air dry	moderately easy	easy	easy	moderately smooth	easy	slightly rough	easy	rough
M. indica	Green	slightly difficult	easy	easy	tangential: smooth; radial: rough	difficult	rough	–	–
	Air dry	easy	easy	easy	moderately smooth	difficult	rough	–	–

NAILING PROPERTY

The nailing property is excellent.

AIR DRYING

The wood seasons fairly rapidly with very few defects. Slight bowing, end-checking, splitting, cupping and some insect attacks are the main sources of degrade. 13 mm thick boards take an average of 3 months to air dry while 38 mm thick boards take an average of 4 months.

KILN-DRYING

Kiln Schedule F is recommended.

Kiln Schedule F

Moisture Content (%)	Temperature (Dry bulb)		Temperature (Wet bulb)		Relative Humidity(approx.) (%)
	� F	� C	� F	� C
Green	120	48.5	111	44	75
60	120	48.5	109	43	70
40	125	51.5	109	43	60
30	130	54.5	109	43	50
25	140	60.0	115	46	45
20	155	68.0	124	51	40
15	170	76.5	136	58	40

SHRINKAGE

Shrinkage is fairly low, with radial shrinkage averaging 1.1% and tangential shrinkage averaging 1.9%.

DEFECTS

The logs are generally free from defects except for borer attacks, which are confined to the sapwood.

USES

The wood is suitable for light construction, planking, flooring, packing boxes and crates, plywood, pallets (expendable as well as permanent and light duty type), posts, beams, joists, rafters and cooling tower (non-structural members). The streaky corewood is highly prized as a decorative wood and is used for high class cabinet work, interior finishing, panelling, mouldings, partitioning, furniture, ornamental items and staircase (apron lining, handrails and sprandrel framing).