Deck 13: Reading Precision Sheet Metal Prints

Question 1

A corner with two edges bent in the same direction has internal stresses that can cause a crack at the corner.

Answer 1

TRUE

Question 2

IML is identify middle line of bend.

Answer 2

FALSE

Question 3

A flat pattern is a 3D representing the initial, unfolded part ready for processing with machine tools to create the final part.

Answer 3

FALSE

Question 4

The neutral axis is approximately sixteenths of the thickness from the outside of the bend, depending on the material and other factors.

Question 5

Bend allowance the amount of extra material needed for a bend to compensate for compression during the bending process.

Question 6

The principal plane is the surface from which the bend is formed.

Question 7

CLB is centerline of bend.

Question 8

Sheet metal typically thicker than 6 mm (0.25 in) is called plate.

Question 9

BUP 90° X R. 250 means bend up (BUP) 90° with a .250 bend radius.

Question 10

The term sheet metal refers to metal that has been rolled into a sheet.

Question 11

Sheet metal thickness generally ranges between .03 in. (0.75 mm) and .5 in. (12 mm).

Question 12

The standard ASME Y14.31-2008, Undimensioned Drawings provides the requirements for undimensioned drawings that graphically define objects with true geometry views and predominantly without dimensions. This standard also provides recommendations for drawing and noting bend lines and bend information.

Question 13

OML is over the middle line of bend.

Question 14

The term bent or bend refers to metal being formed using a stake, brake, folder, die, roller, or similar tools.

Question 15

Precision sheet metal prints require close tolerances and bend allowance calculations.

Question 16

Bend allowance is the amount of extra material needed for a bend to compensate for the tension and compression during the bending process.

Question 17

Extremely thin sheet metal thicknesses are referred to as foil or leaf.

Question 18

Cutting material away from a corner can relieve the internal stress brought on by two edges being bent in the same direction.

Question 19

Seam material is added to both ends of a development if it is to have a double lap seam.

Question 20

The term cut refers to any process, such as shearing, punching, laser, water jet, or similar process that is used to remove material.

Question 21

A double bend is a bend between two parallel faces that are coplanar. The term coplanar means flat surfaces lying on the same plane.

Question 22

Electronic assemblies often require ____ to be fabricated.

A) chassis
B) frames
C) shields
D) panels
E) all of the above

Question 23

The amount of bend allowance depends on several factors. Which of the following is not a bend allowance factor?

A) bend radius
B) degree bend
C) type of material
D) material thickness
E) none of the above

Question 24

Corner radius is used to cut away material at a corner to relieve stress and help in the forming process.

Question 25

A circle divided into twelve equal parts makes each part 15° (180° ÷ 12 = 15°).

Question 26

Bend radius is typically added to a sheet metal part to relieve stress, or the tear that occurs when a portion of a piece of material is bent.

Question 27

Bend tangent line is the line where the flat surface of a part is tangent to the bend radius.

Question 28

A flange is a feature added to a sheet metal part to reinforce or stiffen a part edge or to provide a surface for fastening or welding.

Question 29

Applying the bend allowance to each bend in the flat pattern ensures that ____.

A) the accurate bend angle will be adequate
B) the layout drawings which are required for fabrication and preparation of the part have a comparable bend radius variable to the other parts
C) when the material is formed into its final shape, the desired final dimensions can be achieved
D) both a and c
E) none of the above

Question 30

Bend transition refers to the change made between the adjacent surfaces at a bend when the edge of one surface extends beyond the edge of the other surface.

Question 31

There is only one exact way to establish a bend allowance for a specific application, and that is to experiment with the equipment and material to be used.

Question 32

The purpose of ____ is to determine the overall dimension of the flat pattern, so when bent, the desired final dimension is achieved.

A) the bend relief
B) the bend layout
C) material bending
D) allowance variable
E) none of the above

Question 33

When material bends, there is ____ on the inside of the bend and ____ on the outside.

A) stretching, compression
B) compression; bending
C) compression; stretching
D) bending; stretching
E) none of the above

Question 34

A precision sheet metal pattern can be shown on a print ____.

A) with the finished part shown and the flat pattern drawn using phantom lines
B) as a flat pattern
C) as a finished product
D) all of the above
E) none of the above

Question 35

Single, double, wired, and capped are all types of ____.

A) hems
B) truncated cones
C) seams
D) pattern developments
E) none of the above

Question 36

Bend relief is typically added to a sheet metal part to relieve stress, or the tear, that occurs when a portion of a piece of material is bent.

Question 37

A sheet metal part with bend facets for a press break application has the arc divided into a number of equal parts and each part on the arc is connected to the corner forming a series of triangular facets.

Question 38

Sheet metal prints are found in ____ where flat material is used for fabrication into desired shapes.

A) the packaging industry
B) the automobile industry
C) the electronic industry
D) any industry
E) none of the above

Question 39

The amount of extra material needed for a bend to compensate for the compression during the bending process is called ____.

A) the bend relief
B) the bend layout
C) material bending
D) allowance variable
E) none of the above

Question 40

Bend allowance is important when ____.

A) the length of the neutral axis equals the material thickness
B) close tolerances must be held
C) thick material must be bent or formed into desired shapes
D) both b and c
E) none of the above

Question 41

This is a sheet metal feature that creates a curved sheet metal feature in a linear application on flat material or around an axis.

Question 42

Define nesting undimensioned prints.

Question 43

Describe the practice for representing a sheet metal part is with only the formed sheet metal part model and flat pattern.

Question 44

This is a feature used to add strength to or relieve the sharpness of exposed edges, or to connect separate edges or parts together at a seam.

Question 45

Describe the practice for representing a sheet metal part using a flat pattern with manufacturing information extracted to a table.

Question 46

Describe the basic functions of ASME Y14.31-2008, Undimensioned Drawings.

Question 47

Describe a hole table.

Question 48

This is a feature added to a sheet metal part to reinforce or stiffen a part edge or to provide a surface for fastening or welding.

Question 49

Describe the practice of showing the part in its bent form and in flat pattern on a print.

Question 50

Describe the practice for representing a sheet metal part with only the flat pattern, and using rectangular coordinate dimensioning without dimension lines.

Question 51

This is the process of producing a sheet metal part by cutting its entire outside edge in a die with one stroke of the stamping press.

Question 52

Describe the function of grid lines, including recommended grid line spacing and give an example of the general note placed on a drawing to identify the grid lines used.

Question 53

Define nesting blanks.

Question 54

List five common sheet metal seams.

Question 55

Define and describe the proper use of bend instructions according to ASME Y14.31-2008, Undimensioned Drawings, and include a definition and description of principal plane in your discussion, also give at least two examples of bend instructions.

Question 56

Describe the practice of showing the multiviews of the part representing the final bent condition, and the flat pattern reference drawn on one of the views using phantom lines.

Question 57

What factors influence the amount of bend allowance?

Question 58

Describe the practice for representing a sheet metal part in a flat pattern using rectangular coordinate dimensioning without dimension lines and tabular dimensioning.

Question 59

This is a stamping press operation that forms a single-line cut partway across the sheet without removing material.

Question 60

Describe a bend table.

Question 61

This is a press or similar tool used to form a hole or specific shape in sheet metal.

Question 62

How many of the punch ID features does the punch press punch at the same time, if there are four features displayed on the print with punch ID?

Question 63

Describe the tolerances required for use with undimensioned prints.

Question 64

Describe Punch ID, including how punch ID features are located on a print.

Question 65

Describe the function of registration marks, including how registration marks are displayed and dimensioned on a print.

Question 66

Describe the function of dimensional accuracy points, including how dimensional accuracy points are displayed and dimensioned on a print.