Materials (110101j) and material allowances

Question 1

what is a ferrous metal? ex

Answer 1

metal that contains iron contents
mild steel

Question 2

what is a non ferrous metal? ex

Answer 2

metal that does not have iron in it
Aluminum

Question 3

what are some examples of pure metals?

Answer 3

Gold, silver, copper, aluminum these metals are pure and can be found on the table of contents

Question 4

What is a alloy?

Answer 4

Alloy metals are combination metals that have two or more metals.

Question 5

what is expanded metal?

Answer 5

metal that is formed from slitting and expanding diamond shapes.

Question 6

what is another name for hardware cloth and what is it?

Answer 6

Birdscrean, it is wire mesh that is used for fresh air intakes

Question 7

what is perforated metal?

Answer 7

sheets that have been punched by a machine that creates holes and or different shapes for design ( commonly used for acoustic purposes in commercial)

Question 8

what sizes are common for Hardware cloth/Birdscrean?

Answer 8

1/4” x 1/4”
1/2” x 1/2”
1” x 1”

Question 9

when a metal is brittle how is it described?

Answer 9

something that measure the ability to withstand distortion of a metal
(how fragile it is)

Question 10

when a metal is conductive how is it described?

Answer 10

a metal that can transfer electricity through it, or heat and letting atoms flow through it easily

Question 11

when a metal is ductile how is it described?

Answer 11

it can be bent twisted and stretched without losing and properties and without permanent deformation

Question 12

when a metal is elastic how is it described?

Answer 12

the ability to take it to its yield point and for it to return without permanent deformation

Question 13

when a metal is hardened how is it described?

Answer 13

the metal is very strong but very brittle it can withstand a lot of pressure but will become more brittle as this increases

Question 14

when a metal is malleable how is it described?

Answer 14

it can be easily drawn out by hammering or when forces are applied (soft)

Question 15

what is oxidization?

Answer 15

all metals have and oxide layer this is due to the metal coming into contact with oxygen

Question 16

what is galvanic action?

Answer 16

This is a corrosive prosses that results when dissimilar metal come into contact with some kind of electrolyte such as moisture

Question 17

what are some ways that we can prevent galvanic action?

Answer 17

by using some kind of bushing for example a layer of vapor barrier or pain or rubber coatings

Question 18

how is ferrous metal gauged?

Answer 18

by using the U.S standard gauge

Question 19

How are non ferrous metals gauged?

Answer 19

American standard wire gauge, AKA the brown and sharp gauge

Question 20

is galvanized metal gauged the same as mild steel?

Answer 20

Galvanized metal is coated after being made to size therefore it gauges out slightly thicker

Question 21

what is a ration known for cast iron?

Answer 21

Cast iron is > 3% carbon

Question 22

What two ways does black iron come?

Answer 22

Hot rolled and cold rolled

Question 23

what is more accurate for size hot rolled or cold rolled and why?

Answer 23

cold rolled is more accurate as its procedure of forming is more forgiving and distortion is taken into account and is prevented as best as possible.

Question 24

When is a metal sheet considered to be a plate?

Answer 24

after 1/8” thickness

Question 25

can zink-coated metal be used in food aspects?

Answer 25

no, they are poisonous

Question 26

what are some different ways that galvanized coatings are added?

Answer 26

electro galvanizing or hot dip or cold galvanizing

Question 27

what does electro galvanizing make, trade name?

Answer 27

Satin coat, paint lock, wipe coat

Question 28

what is galvalume good for?

Answer 28

great for venting solutions as it is corrosion resistant

Question 29

what are common types of stainless grades?

Answer 29

304 ( dull not polished) - 316 ( finished )

Question 30

what is the bend radius for aluminum to avoid fracturing?

Answer 30

3x material thickness

Question 31

how is copper gauged?

Answer 31

by the weight in ounces per square foot

Question 32

what are the alloys of brass?

Answer 32

copper and zinc

Question 33

what is thermosetting plastic described as?

Answer 33

plastic that hardens underheat

Question 34

what is thermosetting plastic described as ?

Answer 34

softens when heated and hardens when cooled

Question 35

what are the advantages of fiberglass ductwork?

Answer 35

they have great insulating properties and they are light weight

Question 36

why is flex duct with insulation good?

Answer 36

because it allows for the run to be insulated so it does not lose and thermal properties

Question 37

mild steel is AKA what?

Answer 37

low carbon steel

Question 38

why is flex duct not good?

Answer 38

high amount for friction loss

Question 39

what is the formula for an id measurement?

Answer 39

add 20% of the material thickness to their side of the bend line
(in add 20)

Question 40

what is the formula for an OD measurement?

Answer 40

subtract 80% of the metal thickness on all sides of the bend
(out sub 80)

Question 41

what is mean diameter?

Answer 41

the measurement of the middle of the circumference (actual diameter

Question 42

what is relevant to the mean diameter for ID and OD measurements?

Answer 42

that you adda metal thickness to OD and subtract one for ID