Metals such as gold, silver, copper, and alluminim in their pure form are known as?
Metallic Elements
What are the common hardware cloth sizes?
1/4” x 1/4”, 1/2” x 1/2”, 1” x 1”
If a metal is formed while cold it is?
Cold worked
Rust happens from?
Oxidation
Ferrous metals or metals with iron are gauged using?
The U.S. Standard Gauge
Non-ferrous metals are gauged using?
American Standard Wire Gauge, also known as Brown & Sharpe Gauge
What are the two basic groups of metals?
Ferrous and non-ferrous
Mild steel as also known as?
Low carbon steel
What are some structural steel shapes?
Angle iron, channel iron, flat bar, square and round tubing
What is pickling?
A cleaning process that uses either sulphuric or hydrochloric acid to remove impurities, stains and scale from surface
What is steel plate?
Black iron that measures more than 1/8”
What illness is caused by zinc oxide fumes?
Zinc chills or metal fume fever
Steel sheets that have zinc added to them by electrogalvanizing go by what trade names?
Satincoat, paintlock, and wipecoat
What are two types of zinc-alloy coated sheets?
Galvalume & galvanneal
When working with stainless steel, all work areas should be free of what?
Iron
To avoid fracturing, aluminum should be bent using a bend radius of?
X3 the material thickness
When copper oxidizes it forms a greenish coating that is called?
Patina
What is “UL”
Underwriters Laboratories
Two examples of how PVC duct can be joined together?
Thermal welding & flanging and bolting
Disadvantage of flexible duct?
Extremely high friction loss
