Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Sheet Metal 3rd Year > Basic Fabrication > Flashcards

Basic Fabrication Flashcards

1
Q

What are transitional fittings used for ?

A

Are used to change the aspect ratio and to move duct for architectural reasons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Why is the use of transitional fittings avoided?

A

Time and money

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the 3 types of joints used to join transitional fittings ?

A
  • Slip and drive
  • cp
  • proprietary connection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Why must the slip and drive joint be adjusted on transitional fittings ?

A

Because the 1” slip cannot be at an angle to the next fitting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

You must reduce the length of the net pattern by ____ for each slip and drive connection

A

1”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

When developing the piece for a 2 side flat transition. What should determine which sloped side gets pocket allowances ?

A

The side that has the most amount of slope because there is less angle for transfer of angle notch.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why would blocking be used when assembling a transitional fitting with raw edges ?

A
  • form seams and edges

- open pittsburgh locks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Why would the throat and heel be fastened to one cheek instead of fastening both cheeks to either the throat or the heel?

A

The throat or heel can help support the cheek during assembly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What portion of a plan view for a rectangle to round fitting needs to be developed if the round portion is flat on top and centred in the other direction?

A

1/2 plan view

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

When is it advisable to use more then 12 element points for a square to round fitting ?

A

If the diameter is over 12”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

When laying out a pattern for a square to round fitting that is centred you need to lay out how much of the pattern ?

A

1/4 pattern for the fitting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why should construction lines be on the inside ?

A

Makes for a neater job

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

When folding the allowance for a grooved seam what should you always do?

A

Fold slightly less than its nominal size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the first step when completing a groove seam?

A

Dress the hooked material down to 4 metal thicknesses using a smooth hammer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the material removed by the plasma called ?

A

Kerf

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the power source of the plasma ?

A

Silicon controlled rectifiers or inverters called plasma aggregates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What shade of eye protection should be used with the plasma ?

A

Eye protection or dark goggles that have a shade from 7-9

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is auto nesting ?

A

Auto nesting allows you to optimize material usage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is a duty cycle ?

A

Rated as a percentage of a 10 minute period

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the consumables on a plasma ?

A

The nozzle and the electrode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is a good rule of thumb when cutting with the plasma ?

A

Choose a machine class that is 2 times your cutting thickness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is needed to change the size of the plasma arc ?

A

Amperage, voltage, gas flow and velocity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How are nozzles sized ?

A

According to amperage rating

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What do slow cutting speeds produce ?

A

Vertical lag lines that are perpendicular to the plane of the plate

25
Q

What do fast cutting speeds do??

A

Make slanted - s shape lag lines that run parallel to the plate on the bottom edge

26
Q

How should dross be removed ?

A

By grinding or filing mechanically to minimize the wearing out of equipment parts

27
Q

What is the most important piece of PPE to wear ?

A

A welding helmet

28
Q

why is argon dangerous in an enclosed space ?

A

Because it is heavier than air and can displace oxygen

29
Q

What 3 procedures are required before returning an empty compressed gas cylinder ?

A
  • close the valve completely
  • install the protective cap
  • replace any valve plugs or caps
30
Q

What are 3 advantages of GTAW?

A
  • ability to join most weldable metals
  • most welds are high quality
  • the heat source and filler can be controlled separately
31
Q

What is the most common gas used for GTAW?

A

Argon

32
Q

What color is 2% thoriated tungsten coded?

A

Red

33
Q

What color is pure tungsten coded?

A

Green

34
Q

What polarity is used when welding steel?

A

DCSP or DCEN

35
Q

What may cause a lack of fusion ?

A
  • arc length too long
  • current setting too low
  • incorrect joint preparation
  • poor joint alignment
36
Q

Why is it better to make proper round template before starting to brake form an aluminum square to round?

A

Shaping is easier to control which makes tracking easier

37
Q

Why is it good trade practice to weld 4 piece fittings on the centre of the conical portion?

A

Proper fit and shaping is easier.

38
Q

What is the most common method to minimize warping when welding aluminum?

A

Increase the distance between welds

39
Q

What color is 1% thoriated tungsten coded?

A

Yellow

40
Q

What polarity is used when welding aluminum ?

A

AC

41
Q

What is the most common symptom of inadequate or wrong type of gas flow ?

A

Tungsten is immediately consumed

42
Q

What tungsten would be the best to use on 1/8” thick aluminum ?

A

1%

43
Q

What should you do when using a band saw to cut aluminum?

A
  • use proper coolant
  • listen to the saw
  • keep blade tight
44
Q

A shear is rated for 16ga mild steel. What is the rating for stainless steel?

A

20ga

45
Q

When forming or cutting stainless, equipment must be de rated by how many gauges ?

A

4ga

46
Q

Iron dust contamination can cause what to happen to stainless steel?

A

Rust

47
Q

When bending stainless you need to compensate for _______ by over bending

A

Spring back

48
Q

What is the best advantage of using an air bending dye over a 90 degree v-dye for bending acute angles ?

A

Less pressure is required

49
Q

In which series do austenitic steels belong ?

A

300 series

50
Q

What is the most common group of stainless steel used today?

A

Austenitic

51
Q

What should be done when using a band saw to cut stainless?

A

Lower blade speed

52
Q

What method of bending should be used when power braking ?

A

Air bending

53
Q

Can stainless steel be soldered ?

A

Yes

54
Q

Can stainless steel be polished to a mirror finish?

A

Yes

55
Q

What settings must be done prior to spot welding stainless steel?

A

Increase pressure, decrease current

56
Q

What is the best method of welding stainless ?

A

GTAW

57
Q

What are some methods of distortion control on stainless Steel?

A

Copper chill plates, skip welding , step back welding

58
Q

What are the 4 steps in finishing stainless steel?

A

Grind, sand, polish, buff

Sheet Metal 3rd Year (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions