Deck 16: Sheet Metalworking

Question 1

Sheet metalworking includes both forming and cutting operations:

Answer 1

True

Question 2

Typical sheet-metal thicknesses are between 0.4 mm (1/64 in) and 6 mm (1/4 in).When thickness exceeds the upper limit of this range, the stock is usually referred to as which one of the following:

A)bulk stock
B)oversized sheet
C)plate
D)thick sheet

Answer 2

plate

Question 3

Most sheet metalworking operations are performed as which one of the following:

A)cold working
B)hot working
C)warm working

Answer 3

cold working

Question 4

Most sheet-metal operations are performed on machine tools called stamping presses, and the associated tooling is called a punch and die:

Question 5

In a sheet-metal cutting operation used to produce a flat part with a hole in the center, the part itself is called a blank, and the scrap piece that is cut out to make the hole is called a slug:

Question 6

As sheet-metal stock hardness increases in a blanking operation, the clearance between punch and die should be

A)decreased
B)increased
C)remain the same

Question 7

A circular sheet-metal slug produced in a hole punching operation will have the same diameter as the

A)die opening
B)punch

Question 8

The cutting force in a sheet-metal blanking operation depends on which mechanical property of the metal (one correct answer):

A)compressive strength
B)modulus of elasticity
C)shear strength
D)strain rate
E)tensile strength
F)yield strength

Question 9

Which of the following descriptions applies to a V-bending operation as compared to an edge-bending operation (two best answers):

A)costly tooling
B)inexpensive tooling
C)limited to 90 $\degree$ bends or less
D)used for high production
E)used for low production
F)uses a pressure pad to hold down the sheet metal

Question 10

Sheet-metal bending involves which of the following stresses and strains (two correct answers):

A)compressive
B)shear
C)tensile

Question 11

Which one of the following is the best definition of bend allowance:

A)amount by which the die is larger than the punch
B)amount of elastic recovery experienced by the metal after bending
C)safety factor used in calculating bending force
D)length before bending of the straight sheet-metal section to be bent

Question 12

Springback in a sheet-metal bending operation is the result of which of the following (one best answer):

A)elastic modulus of the metal
B)elastic recovery of the metal
C)overbending
D)overstraining
E)yield strength of the metal

Question 13

Which of the following are variations of sheet-metal bending operations (two best answers):

A)coining
B)flanging
C)hemming
D)ironing
E)notching
F)shear spinning
G)trimming
H)tube bending

Question 14

The following are measures of feasibility for several proposed cup-drawing operations.Which of the operations are likely to be feasible (three best answers):

A)DR = 1.7
B)DR = 2.7
C)r = 0.35
D)r = 0.65
E)t/D_b = 0.5%
F)t/D_b = 2% where DR = drawing ratio r = reduction t = stock thickness and D_b = blank diameter

Question 15

The holding force in drawing is most likely to be

A)greater than
B)equal to
C)less than the maximum drawing force

Question 16

Which one of the following processes uses a thick rubber pad to form sheet metal over a positive form block:

A)embossing
B)Guerin process
C)hydroforming
D)lancing
E)stretch forming

Question 17

Which one of the following stamping dies is the most complicated:

A)blanking die
B)combination die
C)compound die
D)edge-bending die
E)progressive die
F)V bending die

Question 18

In a blanking die, the device that clears the sheet metal from the punch after blanking is called which one of the following:

A)clearance device
B)punch holder
C)stop
D)stripper
E)upper shoe

Question 19

Which one of the following press types is usually associated with the highest production rates in sheet-metal-stamping operations:

A)adjustable bed
B)open back inclinable
C)press brake
D)solid gap
E)straight sided

Question 20

Which of the following processes are classified as high-energy-rate forming processes (two best answers):

A)electrochemical bending
B)electromagnetic forming
C)electron beam deep drawing
D)explosive forming
E)Guerin process
F)hydroforming
G)redrawing
H)shear spinning