1. Tell us why Are Machine Beds Made Of Cast Iron?
Because it has more compressive strength and negligible shrinkage. It can easily cast into any integral shape, wear resisting and can absorb vibrations.
2. Tell me what Do You Mean By Stainless Steel?
It is an alloy steel which contains mainly 8% Nickel and 18% Chromium. Stainless steel main applications in measuring and surgical instruments.
3. Tell us what do you understand by Specific Gravity and Tenacity?
Specific Gravity . It is the ratio of the mass of 1cubic cm. of a substance to the mass of the same capacity of water.
Tenacity .It is the property of metal due to which a metal becomes strong enough to resist the pulling force.
4. Do you know how is steel classified?
According to carbon percentage
☛ Low carbon steel : Less than 0.25% carbon
☛ Medium carbon steel: 0.25%0.7% carbon
☛ High carbon steel: 0.7%1.5% carbon
According to percentage of alloying elements
☛ a. Low alloy steel: Alloying element less than 8%
☛ b. High alloy steel: Alloying element more than 8%
5. Tell us how Does Carbon Affects The Properties Of Steel?
If carbon content is higher the degree of hardness is more and the melting point is lower, If carbon percentage is lower it is easy to forging and forge welding.
6. Tell me why are the delicate parts quenched in oil?
To avoid cracks on the part.
7. What is Hardness Of The Metal?
It is the property of the metal which makes a metal capable to resist surface penetration by other metals .Hard metals are High carbon steel and High speed steel.
8. Tell me what are the chemical composition of Gun metal, German silver and Duralumin?
☛ Gun metal is an alloy of 88% copper, 10% tin and 2% zinc. It is generally used for casting boiler fittings, bearings ,bushes etc.
☛ German silver is an alloy of copper, nickel, tin and led. It is used for making utensils and resistances in electrical work.
☛ Duralumin is the aluminium alloy contains 3.54.5% copper,0.40.7% magnesium,0.40.7% manganese and remaining aluminium .Mainly used for making bars, tubes, rivets, sheets ,forgings and stampings.
Malleability is the property of the metal on account of which it can be extended in all directions by hammering or rolling. E.g.: Tin, Lead
10. Tell me what Are The Differences Between Brass And Bronze?
Brass is an alloy of copper and zinc. Generally brass contains 60% copper and 40% zinc. These are used for making bearings, pump fittings, bushes and utensils.
Bronze contains copper and tin. It is comparatively hard, surface wear is less, can be remolded into any shape like wires, sheets, rods etc.
