Manufacturing Engineering Multiple Choice Questions on “Forging Operations-1”.
1. In which of the following forging operation no special die is used?
a) Drop forging
b) Smith forging
c) Coining
d) Press forging
Answer: b
Clarification: Smith forging is also called flat die and open die forging. It includes the broad field of forging work produced between flat faced dies and possibly supplemented by stock tooling. The final shape of the forging depends on the skill of the smith for size and shape. Smith forging produces work pieces of lesser accuracy as compared to impression or closed die forging. Tooling is simple, inexpensive and allows the production on large variety of shapes.
2. In which of the following forging operation repeated hammering and closed die is used?
a) Drop forging
b) Smith forging
c) Coining
d) Press forging
Answer: a
Clarification: Hammer forging is also called as drop forging where a hammer hits the work piece repeatedly to deform it. There are different types of hammers like gravity drop, counter blow and powder hammers.
3. In which of the following forging operation instead of repeated hammering gradual force is applied?
a) Drop forging
b) Smith forging
c) Coining
d) Press forging
Answer: d
Clarification: Press forging is variation of drop-hammer forging. Unlike drop-hammer forging, press forges work slowly by applying continuous pressure or force. The amount of time the dies are in contact with the workpiece is measured in seconds (As compared to milliseconds of drop-hammer forges). The press forging operation can be done either cold or hot. The main advantage of press forging, as compared to drop-hammer forging, is its ability to deform the complete workpiece.
4. Coining and forming are two special kinds of which forging operation?
a) Upset
b) Press
c) Hubbing
d) Swaging
Answer: b
Clarification: Coining is a severe metal squeezing operation in which the flow of metal occurs at the top layers of the material and not throughout the values The operation is carried out in closed dies mainly for the purpose of producing fine details such as needed in minting coins, and metal or jewellery making. The blank is kept in the die cavity and pressure as high as five to six times the strength of material is applied. Depending upon the details required to be coined on the part, ore than one coining operation may be used.
5. Which of the following forging operation is used for parts having uniform cross section?
a) Upset
b) Press
c) Hubbing
d) Swaging
Answer: a
Clarification: In upset forging, a bar of uniform cross section usually round, is held between grooved dies, pressure is applied on the end in the direction of the axis of the bar by using a heading tool which spreads the end by metal displacement.
6. In which of the following technique shaping of a cross section of tubes or rods is done by means of repeated impacts or blows?
a) Upset
b) Press
c) Hubbing
d) Swaging
Answer: d
Clarification: Swaging is a mechanical deformation technique of reducing or shaping the cross section of rods or tubes by means of repeated impacts or blows.
7. Heading is a kind of which forging operation?
a) Piercing
b) Embossing
c) Upsetting
d) Coining
Answer: c
Clarification: A heading tool or ram is positioned perpendicular to the cross sectioned end face of a rod or bar gripped in a die. On application of pressure, the length of the rod is reduced, and the diameter is increased (upset). This manufacturing process used extensively in the production of fasteners, to form bolt heads, screw heads etc.
8. In heading to avoid buckling the length to diameter ratio should be?
a) 1:3
b) 2:3
c) 3:1
d) 2:1
Answer: c
Clarification: Buckling is characterized by a sudden sideways failure of a structural member subjected to high compressive stress, where the compressive stress at the point of failure is less than the ultimate compressive stress that the material is capable of withstanding. In upset forging, the aspect ratio (length to diameter ratio) should be 3:1.
9. Which operation is used in making raised figures on sheets with its corresponding relief on the other side?
a) Roll forging
b) Embossing
c) Coining
d) Heading
Answer: b
Clarification: Embossing is an operation in which sheet metal is drawn to shallow depths with male and female matching dies. The operation is carried out mostly for the purpose of stiffening flat panels. The operation is also sometimes used for making decoration items like number plates or name plates, jewellery, etc. Embossing operation with two dies, letters, numbers and designs on sheet-metal parts can be produced by the is operation.
10. Which of the following operation is used to make ball bearing?
a) Skew rolling
b) Roll forging
c) Press forging
d) Upsetting
Answer: a
Clarification: A special type, skew rolling is used to manufacture milling steel ball, bearing ball blanks.