BDC - Metals

Question 1

whats the difference between hit rolled and cold rolled steel?

Answer 1

Hot: Tends to eliminate flaws
Cold: increases strength & elastic limits but decreases ductility.

Question 2

what is ductility?

Answer 2

ductility is a solid material’s ability to deform under tensile stress; this is often characterized by the material’s ability to be stretched into a wire

Question 3

what is annealing?

Answer 3

a process in which metal is reheated & slowly cooled to obtain a more ductile metal.

Question 4

what is quenching?

Answer 4

this involves heating the metal to certain temperatures and then rapidly cooling it. this strengthens the steel.

Question 5

what is Tempering (metals)?

Answer 5

similar to quenching but doesnt involve a rapid cooling . it also is used to improve the stength and workability of steel.

Question 6

What is galvanic action

Answer 6

It’s the corrosion resulting when dissimilar metals come in contact with each other in the presence of an electrolyte like water.

Question 7

what is the order of Galvanic series?

Answer 7

Zinc
Galvanized Steel
Alum
Steel & Iron
Stainless Steel
lead
tin
copper alloys
copper

Question 8

what is ferrous metal?

Answer 8

they contain a substantial amount of iron

Question 9

what is non ferrous metal?

Answer 9

are those that do not contain iron, Aluminum, copper brass and bronze are an prime example.

Question 10

what is wrought iron?

Answer 10

used in ornamental metalwork. has low carbon, its soft, ductile and resistant to corrosion.

Question 11

what is cast iron?

Answer 11

has carbon content over 2%, with a high content of carbon its very hard but brittle.

Question 12

what is ductility?

Answer 12

its a property of metals that allows steel to withstand excessive deformations due to high tensile stresses without failure.

Question 13

what are the carbon content for:
Low Carbon Steel:
Medium Carbon Steel:
High Carbon Steel:
Standard Structural Steel:

Answer 13

Low Carbon Steel: .06-.30%
Medium Carbon Steel: .30-.50%
High Carbon Steel: .50-.80%
Standard Structural Steel: .20% to .50%

Question 14

what would a steel designation of ASTM A36 mean?

Answer 14

the yield point is ~36ksi

Question 15

what is stainless steel?

Answer 15

its an alloy containing a minimum of 11% chromium. Sometimes nickel is added.

Question 16

what does AISI stand for in steel?

Answer 16

American Iron & Steel Institute.

Question 17

What are 5 different types of polished finishes?

Answer 17

No. 3: an intermediate, dull finish
No. 4: a general purpose polished finish that is dull and prevents mirror reflections. Its the most frequently used.
No. 6: A dull satin finish
No. 7: a highly reflective finish
No. 8: the most reflective finished surface, used for mirrors and reflectors.

Question 18

whats does ASTM stand for?

Answer 18

American Society of Testing Materials.

Question 19

what is bronze?

Answer 19

its copper & tin

Question 20

what is Monel copper?

Answer 20

its a proprietary metal of copper and nickle. its resistant to corrosion and used on roofing applications.

Question 21

how are wide flanges sized/ designated?

Answer 21

W Depth (inchs) x weight in per feet (lb/ ft)

Question 22

What are steel shape designations?

Answer 22

W = Wide Flange
C = Channel
WT = Structural T
S = Standard I beam
L = Angles
PL = Plate
TS - Tube steel

Question 23

what the difference between steel bars and plates

Answer 23

Bar = under 6"
plate = over 8"

Question 24

what are the 3 types of open web joists?

Answer 24

K = Standard, span 8-60'
LH = Long Span-25-96'
DLH = Deep Long Span 89'-144'

Question 25

in spiral stairs how many treads = 360 deg? in 30 deg segments?

Answer 25

12