Machang


INTRODUCTION

The Standard Malaysian Name for the timber 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 timber is a Light Hardwood with a density of 545-610 kg/m3 air dry.


NATURAL DURABILITY

The timber 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 timber 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 timber 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 timber 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 timber 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 timber 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 timber and is used for high class cabinet work, interior finishing, panelling, mouldings, partitioning, furniture, ornamental items and staircase (apron lining, handrails and sprandrel framing).


REFERENCES

  1. Engku Abdul Rahman Chik. 1998b. Basic and Grade Stresses for Strength Groups of Malaysian Timbers. Malayan Forest ServiceTrade Leaflet No. 38. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur. 13 pp.
  2. Lopez, D. T. 1982. Malaysian Timbers - Machang. Malaysian Forest Service Trade Leaflet No. 68. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur. 8 pp. 
  3. 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.
  4. MS 544:Part 2:2001. Code of Practice for the Structural Use of Timber: Permissible Stress Design of Solid Timber.
  5. Tam, M. K. 1982. Unpublished report.
  6. 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.