308A Metal Types and Properties 5

Question 1

What is the primary reason for specifying a particular 'temper' of aluminum sheet for a sheet metal project?

Accepted Answer

To ensure the aluminum has the correct combination of strength and formability for the intended application

Answer

For colour selection

Answer

For weight reduction only

Answer

Temper does not affect aluminum properties

Question 2

What does the designation '3003-H14' mean for aluminum sheet?

Accepted Answer

Alloy 3003, half-hard temper — a general-purpose alloy that has been strain-hardened to half the maximum hardness

Answer

It weighs 3003 grams and is 14 mm thick

Answer

It is 3003 feet long and 14 inches wide

Answer

A serial number for inventory tracking

Question 3

What is 'lead-coated copper' and what is it used for?

Accepted Answer

Copper sheet coated with lead to provide enhanced corrosion resistance and a uniform grey patina for architectural use

Answer

Copper painted with lead paint

Answer

Lead sheet wrapped around copper pipe

Answer

A solder alloy

Question 4

What is the coefficient of thermal expansion and why is it important for sheet metal installations?

Accepted Answer

It indicates how much a metal expands or contracts with temperature change, which must be accommodated in design to prevent buckling or joint failure

Answer

It measures sound absorption

Answer

It measures electrical resistance

Answer

It is only important for plastic ducts

Question 5

What is the purpose of a 'mill test report' (MTR) for sheet metal materials?

Accepted Answer

To certify the chemical composition, mechanical properties, and specifications of the metal as manufactured

Answer

To report the age of the mill equipment

Answer

To record the mill's production schedule

Answer

To provide maintenance instructions

Question 6

What is the difference between hot-rolled and cold-rolled steel sheet?

Accepted Answer

Hot-rolled is formed at high temperature with a rougher finish; cold-rolled is further processed at room temperature with tighter tolerances and smoother finish

Answer

They are the same product

Answer

Cold-rolled is always thicker

Answer

Hot-rolled is more expensive