Indian Timber Trees

Various Indian timber trees are as follows:

1. Babul:

• It is used for bodies and wheels of bullock carts, agricultural instruments, tool handles, well kerbs, etc.
• It is used for making cabinets.

2. Banyan:

It is used for aerial roots for tent poles, well curbs, etc.

3. Benteak:

It is used for building construction, boat construction, furniture, etc.

4. Deodar:

It is used for making cheap furniture, railway carriages, railway sleepers, packing boxes, structural work, etc.

5. Guava:

It is used for making toys, handles of instruments, engraving work, etc.

6. Hopea:

It is used for ordinary house construction, railway sleepers, piles, boat building, etc.

7. Kathal:

• It is not attacked by white ants.
• It is used for piles, platforms of wooden bridges, door and window panels, etc.

8. Mulberry:

It is strong, tough and elastic. It takes up a clean finish. It can be well seasoned. It is turned and carved easily. Its weight after seasoning is about 650 kg/m3. It is found in Punjab. It is used for baskets and sport goods like hockey sticks, tennis rackets, cricket bats, etc.

9. Oak:

It is used for preparing sport goods.

10. Rosewood or Blackwood:

It is used for furniture of superior quality, cabinet work ornamental carvings, etc.

11. Sal:

It is used for railway sleepers, ship building, bridges, structural work, etc. Sal poles are used as foundation piles.

12. Sissoo:

It is used for high class furniture, plywoods, bridge piles, sport goods, railway sleepers, etc. It is a very good material for decorative works and carvings.

13. Toon:

It is used for furniture, packing boxes, cabinet making, door panels, etc.

WROUGHT IRON

• It is obtained by removing impurities from the cast iron and is considered to be the pure iron.
• The total impurities are limited to 0.5% with maximum carbon content of 0.15%, silicon 0.15 – 0.2%, phosphorous 0.12 – 0.16%, sulphur 0.02 – 0.03%, manganese 0.03 – 0.1%.
• It is produced in a reverberatory (or puddling) furnace.
• The molten iron is first refined by blasting air in the furnace.
• The metal is then cooled down and poured into moulds. This metal becomes brittle.
• This metal is melted in furnace where the metal melts due to burning of gas.
• After melting, puddle balls are produced which are sent for shingling.
• The balls are sent to groove rollers to form flat bars. This process is repeated several times to remove the impurities.

Properties of Wrought Iron

• It is ductile, malleable, tough and is moderately elastic (modulus of elasticity 1.86 x 10⁶ N/mm²).
• Its ultimate compressive strength is about 200 N/mm2 and tensile strength is about 40 N/mm².
• Transverse to the direction of rolling, the tensile strength ranges from 60 – 85% of its tensile strength in longitudinal direction.
• Melting point of wrought iron is 1500°C and specific gravity 7.8.
• Unlike cast iron, it can be forged and welded.
• It resists corrosion effectively.
• It is tough and can withstand shocks.
• At a temperature of about 900°C, it becomes so soft that its two pieces can be joined by hammering.
• Alloying elements that are used with wrought iron are nickel (Ni), copper (Cu) and molybdenum (Mo).
• Nickel in quantities of about 1.5 – 3.5% substantially increases the elastic limit and tensile strength.
• Nickel also helps in preventing the reduction of impact strength at sub-zero temperatures.
• Copper when added to wrought iron increases the corrosion resistance property.