Mechanical Workshop VIVA QUESTIONS PDF

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Mechanical Workshop VIVA QUESTIONS REGARDING CASTING WELDING ARA AND GAS DEFECTS...

Description

Machining is a process in which a material (often metal) is cut to a desired final shape and size by a controlled material-removal process 

Tools Required for machining:

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Broaching machine. Drill press. Gear shaper. Hobbing machine. Hone. Lathe. Screw machines. Milling machine. Hone. Shear. Shaper. grinding machine

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A casting process involves pouring molten metal into a mold, letting the metal cool and solidify, and removing the part from the mold. From: Exploring Engineering (Third Edition), 2013.

TYPES OF CASTING DEFECTS     

Gas Porosity: Blowholes, open holes, pinholes. Shrinkage defects: shrinkage cavity. Mold material defects: Cut and washes, swell, drops, metal penetration, rat tail. Pouring metal defects: Cold shut, misrun, slag inclusion. Metallurgical defects: Hot tears, hot spot.

Tools used in carpentry workshop? holding and supporting tools in a carpentry shop.

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Work Bench. Every carpenter needs a solid bench or table of hardwood on which he can carry out carpentry operations. ... Carpenter Vice. used for holding wooden jobs

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Clamps. used in pairs for gluing up operations ,clamps can provide the required pressure to

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hold joints together   

Hammer. deliver an impact or force to an object Screwdriver used for driving screws into materials Tape Measure used to measure the length of wood

Difference between Arc Welding and Gas Welding:

Gas Welding S.No.

3. 4. 5. 6. 7. 8.

Arc Welding In the arc welding, electricity is used to generate heat. This welding generates higher temperature than gas welding. The temperature is about 6000C. This welding generates stronger joint compare to gas welding. It gives poor surface finish. In arc welding consumable electrode is used. The electrode is combined with the filler metal. It can be used in welding alone. There is risk of explosion due to high voltage.

9.

It is mostly used to joint similar material.

10. 11. 12. 13.

The heat is concentrate in arc welding. It is more efficient. Speed of welding is high. The initial cost of arc welding is high.

1. 2.

In gas welding, fuel gases like acetylene, hydrogen are used to generate heat. This welding generates lower temperature than arc welding. The temperature is about 3600C. It gives weaker joint. This welding gives good surface finish. In gas welding non consumable electrode is used. A filler rod is used separately if required. It can be used in welding, brazing and soldering. There is risk of explosion due to high pressure. It is mostly use to join both similar and different metals. The heat is distributing according to the flame. There is higher loss of energy. It is less efficient. Speed of welding is low. The setup cost of gas welding is low....