Chapter 7 metals

Question 1

Decorative Metals

Answer 1

Include a wide variety of functional and decorative products, including handrails, guardrails, elevator interiors, custom doors, custom light fixtures, and many other building components

- Most commonly used metals are stainless steel, copper alloys (bronze, brass), and aluminum
- Steel, copper, iron, zinc also sometimes used

Question 2

Stainless Steel

Answer 2

Steel alloy containing 12% or more chromium; may also contain nickel, manganese, molybdenum
Highly corrosion resistant, very strong
Available in sheet, plate, strip, bar, angles, channels, tees, and solid shapes. Pipe and tubing also available

Question 3

Pipe vs. Tubing measurement

Answer 3

Pipe: measured by I.D.
Tubing: measured by O.D.

Question 4

Stainless Finishes

Answer 4

Rolled, polished, etched most common

Question 5

Detailing Stainless Steel

Answer 5

• Similar to carbon steel, can be welded, mechanically fastened, sometimes bonded with adhesives
• Fasteners should also be stainless steel to prevent galvanic action

Question 6

3 main types of Copper alloys

Answer 6

• Almost pure copper
• ‘architectural bronze’ or common brasses
• Nickel-silver/silicon bronze alloys

Question 7

Welding

Answer 7

joins two metals by using high temperatures to heat them above their melting points either with or without a filler metal

Question 8

Brass

Answer 8

• Brass is alloy of copper and zinc
• Standard shapes similar to stainless steel available
• Brass is often finished using chemical finishes that alter the surface
• Coatings are applied finishes formed from metal itself

Question 9

Anodic (Anodized) finish

Answer 9

electrochemical process that forms an oxide coating on the metal surface when placed in a bath of chemicals with an electric current

Question 10

Monel Metal

Answer 10

• Nickel-copper alloy, silver-gray color slightly grayer than stainless steel
• Very expensive, highly corrosion-resistant

Question 11

Zinc

Answer 11

• In architectural applications, traces of copper & titanium added to reduce brittleness
• Uniform gray color, can be embossed, hammered, polished, engraved, colored

Question 12

Steel

Answer 12

• Usually used where appearance not a concern; very strong, must be coated/painted where corrosion resistance is required
• Fastened mechanically, using adhesives, and welding

Question 13

Iron

Answer 13

Cast and wrought iron two main types; cast has 1.7% carbon, Wrought has .03-.05%

Question 14

Bronze

Answer 14

• Technically, bronze is an alloy of copper and 2% or more of tin
• Much of what is called bronze in general use is actually a brass alloy
• None of the common alloys used in architectural interiors are true bronzes

Question 15

Brass Fastening

Answer 15

• Brass can be welded, but is normally brazed, soldered, mechanically fastened, and installed with adhesives
• Brazing joins metals at intermediate temperature (800F) using nonferrous fillers
• Soldering uses lead/tin based filler, lower temperature (500F)
• Welding joins metals by melting together at much higher temperatures

Question 16

Aluminum

Answer 16

• Components usually extruded
• Can be made in a wide array of shapes
• Finished using mechanical, chemical, and anodic processes (anodizing)-electrochemical process that forms an oxide coating on metal surfaces
• Fastened mechanically, using adhesives, and welding (usually TIG)

Question 17

Perforated Metal

Answer 17

• Sheet metal punched with regular pattern of holes
  
  • Standard perforations include round, square, and slotted holes
  • Used as space dividers, railing guards, shelving, furniture, air grilles, light fixtures
  • Steel, stainless steel, aluminum commonly available; verify standard available sizes during design process to keep cost, waste to a minimum
  • Note margins, finished edges, staggered vs. straight hole patterns have different appearances

Question 18

Galvanic Series of Metal

Answer 18

• When different metals come into contact, electrical current flows between them, and corrosion of the more active or anodic metal results.
• Avoid direct contact between metals far apart on the galvanic series. The further apart the metals on the list, the greater the electrical potential difference and the greater the potential corrosion. For example, it is relatively safe to have copper and tin in direct contact; but contact between copper and zinc should be avoided
• It is usually safe for fasteners to be more cathodic than the metals they attach. For example, stainless steel fasteners are OK for copper sheet; zinc coated fasteners are not

Question 19

Unified Numbering System (UNS)

Answer 19

used to designate all commercial metals and alloys
- letter prefix to designate general type of metal then followed by a five-digit number that identifies the specific alloy

Question 20

Mechanical finish

Answer 20

alters the surface of the metal by rolling or some other mechanical means

Question 21

Chemical Finishing

Answer 21

alters the surface with chemical processes

Question 22

Coated Finishes

Answer 22

are applied finishes that are formed from the metal itself through chemical or electrochemical conversion or by adding some other materials.

Question 23

Methods of Fastening

Answer 23

joined with mechanical fasteners or adhesives, or by brazing or soldering

Question 24

Mechanical Fasteners

Answer 24

• includes screws bolts, rivets, and various types of clips compatible alloys

Question 25

Brazing

Answer 25

is the joining of two metals at an intermediate temperature above 800 degrees Fahrenheit using a nonferrous filler metal

Question 26

Soldering

Answer 26

joining of two metals using lead-based or tin based alloy solder that melts below 500 degrees Fahrenheit

Question 27

Mechanical Finishes of Aluminum

Answer 27

includes buffed, directional- textured, non-directional textured and patterned

Question 28

Wrought Iron and Cast Iron work

Answer 28

produced by forging, casting, stamping, and hammering to produce custom construction elements

Question 29

Iron is joined……

Answer 29

joined by forge welding, riveting, collaring, and wrapping

Question 30

anodizing

Answer 30

electrochemical process that forms an oxide coating on metal surfaces