Kekatong


INTRODUCTION

The Standard Malaysian Name for the timber of Cynometra spp. (Leguminosae). Vernacular names applied include belangan (Peninsular Malaysia), belangkan (Peninsular Malaysia), katong-katong (Peninsular Malaysia and Sabah) and kekatong laut (Peninsular Malaysia). Major species include C. elmeri, C. iripa, C. malaccensis, C. mirabilis and C. ramiflora. The sapwood is lighter in colour than the heartwood and not well defined from the heartwood, which is red-brown or claret-red with streaks of lighter colour.

Also known as Chom prinh (Cambodia); Moivi and Tongatu (Fiji); Ping (India); Kateng and Kepel (Indonesia); Mai li (Laos); Myinga (Myanmar); Balitbitan and Oringen (Philippines); and Katong and Mang Kha (Thailand).


DENSITY

The timber is a Heavy Hardwood with a density of 880-1,155 kg/m3 air dry.


NATURAL DURABILITY

Based on the standard graveyard test of untreated specimens of dimension 50 mm x 50 mm x 600 mm, the wood is classified as moderately durable under Malaysian climatic conditions. The average service life for 52 untreated specimens of C. malaccensis was about 4.2 years (Mohd. Dahlan & Tam, in press).  


PRESERVATIVE TREATMENT

The timber of kekatong is not amenable to preservative impregnation and is classified as very difficult to treat.


TEXTURE

Texture is moderately fine and uneven, with straight to shallowly interlocked grain.


STRENGTH PROPERTIES

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


Strength Properties of Kekatong (C. malaccensis)

Test Condition

Modulus of Elasticity(MPa)

Modulus of Rupture(MPa)

Compression parallel to grain (MPa)

Compression perpendicular to grain (MPa)

Shear strength(MPa)

Green

17,000

105

56.0

11.03

13.2

Air dry

18,400

135

67.0

11.38

15.6


MACHINING PROPERTIES

It is easy to difficult to resaw and difficult to cross-cut. Planing is easy to slightly difficult and the surface produced is moderately smooth.


Machining Properties of Kekatong (C. malaccensis)

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

Green

easy

difficult

easy

moderately smooth

easy

smooth to rough

-

-

Air dry

difficult

difficult

slightly difficult

moderately smooth

slightly difficult

moderately smooth

difficult

moderately smooth


NAILING PROPERTY

Nailing property is rated as poor.


AIR DRYING

The timber seasons moderately slowly without degrade except for some end-checking. 13 mm thick boards take 3 months to air dry, while 38 mm thick boards take 5 months.


KILN-DRYING

Kiln Schedule B is recommended. 25 mm thick boards can be kiln-dried in 8 days.


Kiln Schedule B

Moisture Content (%)

 Temperature (Dry Bulb)

  Temperature (Wet Bulb)

Relative Humidity (%) (approx.)

F

C

F

C

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 1.6% and 2.7% on the radial and tangential surfaces respectively.


DEFECTS

Desch (1941) recorded that pin holes, end splitting and end checks are common in C. malaccensis logs. Occasional spongy heart at the centre of the logs was also observed. The sapwood of C. malaccensis was reported to be very readily attacked by powder-post beetles (Burgess, 1966).   


USES

The timber is suitable for heavy construction under cover, telegraphic and power transmission posts and cross arms, beams, posts, joists, rafters, door and window frames and sills, flooring (heavy traffic), fender supports, railway sleepers when treated, cooling tower (structural members), staircase (apron linings, balustrades, newels and stringers), vehicle bodies (framework and floor boards), pallets (heavy duty and permanent tyrpes), tool handles (impact) and laboratory benches.


REFERENCES

  1. Burgess, P. F. 1966. Timber of Sabah. Sabah For. Rec. No. 6.
  2. Desch, H. E. 1941. Manual of Malaysian Timbers. Mal. For. Rec. No. 15 Vol. 1.
  3. Engku Abdul Rahman Chik. 1998b. 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.
  4. 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.
  5. Mohd. Dahlan Jantan and Tam, M.K. (in press). Natural Durability of Some Malaysian Timbers by Stake Test. Malay. For.
  6. Mohd. Shukari Midon. 1983. Malaysian Timbers - Kekatong. Timber Trade Leaflet No. 79. The Malaysian Timber Industry Board and Forest Research Institute Malaysia, Kuala Lumpur. 7 pp. 
  7. MS 544:Part 2:2001. Code of Practice for the Structural Use of Timber: Permissible Stress Design of Solid Timber.
  8. 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.