Chlorophora Excelsa (Iroko)


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Scientific Name
Chlorophora excelsa

Trade Name
Iroko

Family Name
Moraceae

Synonyms
Morus excelsa, Chlorophora alba, Chlorophora excelsa, Chlorophora tenuifolia, Maclura excelsa, Milicia africana

Common Names
Abang, African oak, African teak, Agui, Akede, Bakana, Bang, Banghi, Bobang, Bonzo, Bush oak, Bush teak, Bwagashanga, Corkwood, Elowa, Elua, Elui, Emang, Geh, Guele, Guh, Gutumba, Intule, Iroko, Kambala, Kimurumba, Logo asagu, Loko, Lusanga, Mamangi, Mandji, Mbala, Mbara, Mereira, Mgunda, Minarui, Mokongo, Moloundou, Molundu, Moreira, Muberry, Mucoco, Murie, Murumba, Mururi, Mutumba, Mutumbav, Muvule, Mvule, Mvuli, Nsan, Ntong, Obas tree, Odji, Odoum, Odum, Oduna, Ofryio, Olia, Olua, Olwaa, Oroko, Oroko ulokoodigpe, Rock elm, Roco, Rokko, Sanga, Semei, Semli, Sime, Simli, Simme, Ssare, Teak, Tema, Toumbohiro noir, Tule, Tule mufala, Uklobce, Ulok, Uloko-mushinogbon, Ulundu, Vai

Regions of Distribution
Africa

Countries of Distribution  [VIEW MAP]
Angola, Benin, Burundi, Cameroon, Congo, Gabon, Gambia, Ghana, Ivory Coast, Kenya, Liberia, Mozambique, Nigeria, Rwanda, Sierra Leone, Tanzania, Togo, Uganda, Zaire, Zimbabwe

Common Uses
Agricultural implements, Boat building (general), Boat building, Boat building: decking, Boat building: framing, Boat building: planking, Boxes and crates, Bridge construction, Building materials, Cabinetmaking, Canoes, Carvings, Chairs, Chests, Concealed parts (Furniture), Cooperages, Core Stock, Decks, Decorative veneer, Desks, Dining-room furniture, Domestic flooring, Dowell pins, Dowells, Drawer sides, Excelsior, Factory flooring, Figured veneer, Fine furniture, Floor lamps, Flooring, Framing, Furniture , Furniture components, Furniture squares or stock, Furniture, Golf club heads, Hatracks, Heavy construction, Interior construction, Interior trim, Joinery (external): ground contact, Joinery, Kitchen cabinets, Lifeboats, Light construction, Living-room suites, Lock gates, Marine construction, Millwork, Mine timbers, Moldings, Musical instruments: percussion, Office furniture, Paneling, Parquet flooring, Particleboard, Piling, Plain veneer, Plywood, Posts, Pulp/Paper products, Radio – stereo – TV cabinets, Railroad ties, Rustic furniture, Shingles, Stairworks, Tables, Turnery, Vats, Vehicle parts, Veneer, Veneer: decorative, Wheel spokes, Wheels

Environmental Profile

Vulnerable
Vulnerable in parts of its natural habitat
Secure in many areas of its range
Data source is World Conservation Monitoring Center

It is classified as Vulnerable in Cameroon, Ivory Coast, Kenya, and Zimbabwe. It has also been classified as Endangered in Benin and Congo

Heartwood Color

Brown
Yellow
White
Red
Orange
Tan
Brown
Yellow to golden-yellow to orange
Pale brown
Greenish to greyish
Yellow bands
Dark brown

Lighter vessel lines are conspicuous on flat sawn surfaces. Large deposits of calcium carbonate, with darker colored surrounding material are usually present. Yellow bands of soft tissue are reported to form a zig-zag pattern on all surfaces.

Sapwood Color

Red
Brown
Yellow
White
White to yellow
Well defined
Same as heartwood
Paler than heartwood

Grain

Interlocked
Figure
Distinct (figure)
Stripe (figure)
Wavy
Straight
Rippled (figure)
Closed
Even
Mottled (figure)
Growth rings (figure)
Variable (figure)

 

Interlocked
Distinct figure
Wavy
Striped figure
Straight
Rippled figure
Mottled figure
Moderately interlocked
Irregular color
Clear growth rings (figure)

Texture

Fine
Medium
Uniform
Even or uniform
Coarse
Medium to coarse
Medium
Medium coarse and uniform

Luster

Medium
High
Lustrous
Pronounced
Low

Natural Growth Defects

Gum and mineral deposits
Reaction wood may be found

Natural Durability

Perishable
Non-resistant to powder post beetles
Non-durable
Susceptible to insect attack
Very durable
Resistant to attack from termites (Isoptera)
Susceptible to attack from powder post (Lyctid & Bostrychid) beetles
Moderately resistant to termite (Isoptera) attack
Pinworms (ambrosia beetles) often present in the standing tree
Resistant to attack from pinworms (ambrosia beetles)
Resistant to attack from marine borers
Pinworms (ambrosia beetles) are commonly present
Durable
Moderately resistant to marine borer attack
Sapwood susceptible to attack by powder post beetles
Sapwood is highly resistant to termite attack
Resistant to attack from powder post (Lyctid & Bostrychid) beetles
Moderate weathering properties
Heartwood resistant to decay
Heartwood is susceptible to attack by dry-wood insects

Light-Induced Color Change

Darker

Toxicity

Unspecified toxicity
Dermatitic effects
Respiratory effects

Kiln Schedules

Drying (speed) is fast
UK=E US=T6D2/T3D1 Fr=5
Dry at a moderate speed
Kiln Drying Rate (in days) is rapid
Kiln Drying Rate (in days) is fairly rapid
T6 – D2 (4/4) US
T3 – D1 (8/4) US

Drying Defects

Distortion
Slight end splitting
No end splitting
Slight twist/warp
No twisting or warping
Slight surface checking
Distortion (twist/warp) is likely

Ease of Drying

Thick Stock Requires Care
Rapidly
Moderately Difficult to Difficult
Requires special attention
Easy

Kiln Drying Rate

Naturally dries quickly
Rapid (<10 days for boards < 32 mm, to <30 days for boards >= 63 mm)
Fairly rapid (11-17 days for boards under 32 mm, to 31-51 days for boards greater than 63 mm)

Tree Identification

Bole/stem form is buttressed
Bole/stem form is cylindrical
Bole/stem form is not buttressed
Bole/stem form is straight

Tree Size

Tree height is 30-40 m
Bole length is 10-20 m
Tree height is 20-30 m
Bark width is 5-10 mm
Tree height is 40-50 m

Product Sources
The ITTO reports that the species is a regular source of timber. Timber export is regular except in the Ivory Coast where exportation of the material in log form is prohibited.

Iroko is available in moderate quantities in long lengths, wide boards, and in the form of veneers on the European market are priced in the same range as the lower cost hardwoods.

Availability in the U.S. is rather limited, but Iroko is sold at comparatively inexpensive prices when available. Iroko is substituted for Teak in many applications, since it performs just as well as Teak and is less expensive.

Comments
Chemical resistant

General finishing qualities are rated as good

Blunting Effect

Blunting effect on machining is severe
Blunting effect on machining is moderate
Blunting effect on sawing green wood is moderate
Blunting effect on sawing dry wood is moderate
Blunting effect on machining is fairly severe
Severe and rapid blunting effect

Boring

Fairly difficult to very difficult
Easy

Cutting Resistance

Easy to saw
Cutting Resistance with green wood is easy
Easy to saw
Difficult to saw
Cutting Resistance with dry wood is easy

Gluing

Fair to Good Results
Fairly Easy to Very Easy
Easy to glue
Glues well
Casein glue may produce black glue line

Mortising

Fair to Good Results
Fairly Difficult to Very Difficult
Finishes well
Easy to mortise

Moulding

Very Good to Excellent Results
Fairly Difficult to Very Difficult
Fair to Good Results
Easy to mould

Movement in Service

Unstable with Poor Stability – Large Movement
Fair to Good Stability – Medium Movement
Small
Stable

Nailing

Fair to Good Results
Pre-Boring Recommended
Fairly Easy to Very Easy
Very Good to Excellent Results
Easy to nail
Holds nails well
Good nailing properties
Difficult to nail

Planing

Fairly Easy to Very Easy
Fair to Good Results
Very Good to Excellent Results
Good planing results, but can be variable
Easy to plane
Difficult to plane
Areas of interlocked grain may cause tearing

Resistance to Abrasion

Moderate

Resistance to Impregnation

Permeable sapwood
Resistant heartwood
Permeable heartwood
Resistant sapwood
Heartwood is highly resistant
Sapwood is extremely resistant

Response to Hand Tools

Easy to Work
Easy to machine
Moderate working qualities
Variable qualities
Satisfactorily
Difficult to machine

Routing & Recessing

Fairly Difficult to Very Difficult
Routing is easy

Sanding

Good sanding finish
Easy to sand

Screwing

Fair to Good Results
Very Good to Excellent Results
Fairly Easy to Very Easy
Easy to screw
Screwing yields good results
Satisfactory screwing properties

Turning

Fairly Difficult to Very Difficult
Easy to turn

Veneering Qualities

Suitable for slicing
Veneers easily
Veneers moderately easy
Suitable for peeling
Good gluing qualities
Suitable for slicing
Easy to cut
Bolt preparation requires steaming

Steam Bending

Fair to Good Results
Moderate
Good

Painting

Surface degreasing is recommended
Satisfactory results
Poor results

Polishing

Satisfactory results
Good results

Staining

Finish is generally good
Stains well
Some surface preparation needed
Reacts with Iron to discolour wood

Varnishing

Satisfactory after treatment
Poor turning properties

Strength Properties

Density (dry weight) = 38-45 lbs/cu. ft.
Hardness (side grain) = medium
Max. crushing strength = medium
Modulus of Elasticity (stiffness) = very low
Shrinkage, Radial = very small
Bending strength (MOR) = medium
Bending strength (MOR) = low
Shrinkage, Tangential = very small
Shearing strength (parallel to grain) = very low
Density (dry weight) = 46-52 lbs/cu. ft.
Shrinkage, Radial = small
Modulus of Elasticity (stiffness) = low
Shearing strength (parallel to grain) = medium
Max. crushing strength = high
Toughness-Hammer drop (Impact Strength) = low
Max. crushing strength = low
Shearing strength (parallel to grain) = high
Hardness (side grain) = soft
Shearing strength (parallel to grain) = low
Hardness (side grain) = hard
Shrinkage, Tangential = small
Shrinkage, Radial = moderate
Density (dry weight) = 31-37 lbs/cu. ft.
Very heavy
Toughness-Hammer drop (Impact Strength) = very low
Shrinkage, Radial = fairly large
Modulus of Elasticity (stiffness) = medium
Max. crushing strength (stiffness) = very low
Hardness = medium
Density = high
Compression strength (parallel to grain) = high
Bending strength (MOR) = very low
Bending strength (MOR) = high

Numerical Data

Item Green Dry English
Bending Strength 9743 13581 psi
Crushing Strength 1744 psi
Density 42 lbs/ft3
Hardness 1603 lbs
Impact Strength 27 24 inches
Maximum Crushing Strength 4551 7398 psi
Shearing Strength 1604 psi
Static Bending 7889 psi
Stiffness 1231 1569 1000 psi
Toughness 362 inch-lbs
Work to Maximum Load 9 10 inch-lbs/in3
Specific Gravity 0.51 0.7
Weight 44 44 lbs/ft3
Radial Shrinkage 3 %
Tangential Shrinkage 5 %
Item Green Dry Metric
Bending Strength 685 954 kg/cm2
Crushing Strength 122 kg/cm2
Density 673 kg/m3
Hardness 727 kg
Impact Strength 68 60 cm
Maximum Crushing Strength 319 520 kg/cm2
Shearing Strength 112 kg/cm2
Static Bending 554 kg/cm2
Stiffness 86 110 1000 kg/cm2
Toughness 417 cm-kg
Work to Maximum Load 0.63 0.70 cm-kg/cm3
Specific Gravity 0.51 0.7
Weight 705 705 kg/m3
Radial Shrinkage 3 %

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