Concepts Of Production Technology | Gate Mech Basic Concepts
1. Projection welding is multi spot welding process.
2. In resistance welding, the pressure is released after the weld cools.
3. Grey cast iron is best welded by oxy-acetylene.
4. The edge preparation for welding Is not needed up to 4 mm thickness of plate.
5. The relation for cutting tool life is given by VTn = C where V is cutting speed, T is corresponding life n and C are constant depending on cutting conditions. The numerical value of n for roughing cut as compared to that for light cuts in mild steel does not on type of cut.
6. A plug gauge is used to measure cylindrical bores.
7. Aluminum has a higher cutting speed than cast iron & tool steel.
8. A magnetic chuck is generally used when a large number of components are turned and parted off from a bar.
9. Gear tooth vernier is used for measuring gear tooth profile.
10. Undercutting is cutting from the base of a work-piece.
11. Laser welding is widely used in electronic industry.
12. Un- like materials or materials of different thickness can be butt welded by control of pressure and current.
13. In are welding operations the current value is decided by the size of the electrode.
14. The phenomenon of weld decay takes place in stainless steel.
15. Arc below takes place in welding stainless steel.
16. Swab is used in foundry for repairing the mould.
17. Gagger is used in foundry for cleaning of castings.
18. Bellows are used in foundry for smoothening and cleaning out depression in the mould.
19. Permeability of a foundry sand is capacity to hold moisture.
20. What for are metal pattern used in large scale production of castings.
21. An important factor to be considered while designing a core print is moulding sand characteristics.
22. Weld spatter refers to welding defect.
23. If‘t’ is the thickness of sheet to be spot welded, then electrode Tip diameter is equal to √t.
24. A sprue is a tool used in mould repairing.
25. Gate is a vent hole to allow for the hot gases to escape.
26. Core prints provided to from seat to support and hold the core.
27. The equipment that is used in pit for supply of air is known as centrifugal blower.
28. Draft allowance on castings is generally 1-2 mm/M.
29. Tumbling is done so as to clean the surface of small parts.
30. The purpose of inoculation is to modify the structure and properties of a cast metal.
31. The draft allowance on metallic pattern as compared to wooden ones is less.
32. Angle iron is not a angle measuring device.
33. The mould for casting ferrous materials in continuous casting process is made of copper.
34. If V is the volume of metal in a casting and A its surface areas, then time of solidification will be proportional to V2, 1/A2. The purpose of riser is to help feed the casting until all solidification
35. A silver refers to the temperature of equilibrium between solid silver and liquid silver at normal atmospheric pressure.
36. The gold point refers to 10630C.
37. The silver point refers to 960.500C.
38. Rotameter is used for flow of liquids and gases.
39. The impedance of piezo-electric crystal is high.
40. Hot wire anemometers are generally used for measuring velocity of air steam.
41. Scale sensitivity is defined as ratio of a change in scale reading to the corresponding change in pointer deflection.
42. In carthias process cavity is filled with a pre-calculated quantity of metal and a core or plunger is inserted to force the metal in to cavity.
43. In slush casting process metal is poured in to die cavity, and after a predetermined time the mould is inverted to permit a part of metal still in molten to flow out of cavity.
44. Ornaments are cast by gravity casting.
45. During MIG welding the metal is transferred in the form of fine spray of metal.
46. A collimated light beam is used for producing heat in laser welding.
47. Wipping is the process of connecting loss pipes by soldering alloy.
48. In water jet machining process hydraulic fluid acts as transfer media.
49. The power consumption in ultrasonic machining in kW/cm3/min is of the order of 10 kW/m3/min.
50. Sweep pattern is used for moulding parts having uniform symmetrical shape.
51. The helix angle on a HSS (High Speed Steel) twist drill for drilling cast iron is of the order of 24-320.
52. The usual value of helix angle of a drill is 300.
53. A twist drill is specified by shank, material and diameter.
54. Broaching operation is generally used in automobile industry as semi-skilled operators can be employed.
55. For proper broaching operation at least three number of teeth should be in the work at a time.