Division 5: Metals

• Types of Metals


  • Aluminum
  • Iron
  • Steel
  • Copper
  • Tin
  • Zinc
  • Brass
  • Bronze
  • Chromium
  • Nickel
  • Lead
• Aluminum


  A soft, nonmagnetic silvery metal characterized by its light weight (1/3 that of iron, brass or copper), low melting point, high thermal and electrical conductivity (surpassed only by silver and copper), and moderately high coefficient of expansion
• Aluminum


  • Readily combines with oxygen to form aluminum oxide, a transparent film that makes it corrosion resistant
  • Readily attacked by alkalis, hydrochloric acid and other dilute acids
  • Subject to galvanic action and should therefore be electrically insulated from direct contact with metals other than zinc, cadmium, magnesium and nonmagnetic stainless steel
  • Easily worked: can be hot or cold rolled, extruded, forged, pressed, drawn, molded, stamped, bent and shaped
  • Can be riveted, bolted, welded, brazed and soldered
• Aluminum products used in architectural work


  • Rod
  • Bar
  • Extrusion
  • Casting
  • Sheet
  • Strip
• Aluminum products are not fabricated from pure aluminum but in alloy combination with iron, silicon, copper, manganese, magnesium, zinc, chromium and nickel in small quantities to give strength and other desirable characteristics but often reduces its corrosion resistance
• Alclad


  A term applied to certain aluminum products, refers to the protective coating (cladding) applied, primarily for corrosion resistance, to thin sheets of an alloy whose corrosion resistance has been decreased by the constituents added to give strength and other characteristics
• Types of Aluminum


  • Aluminum Foil
  • Corrugated Aluminum
  • Structural Aluminum
  • Aluminum Doors and Windows
  • Aluminum Panels and Sandwich Panels
  • Ornamental Aluminum
  • Aluminum Mesh and Wire Cloth
• Structural Aluminum


  • Can be extruded, allowing structural shapes to be produced economically to meet specified structural design requirements
  • Very corrosion resistant aluminum alloys are available, requiring no painting and the thickness of sections can be reduced since a safety margin is not necessary to cover loss of strength due to corrosion
  • Lightweight material, hence aluminum girders and columns show increased efficiency with large bay spacing, but the modulus of elasticity of aluminum alloys is lower than steel, meaning buckling is a possibility and should always be checked
• Methods of Joining Metals


  • Soldering
  • Brazing
  • Welding
  • Rivets
• Metals for Concrete Reinforcement


  • Steel Bars
  • Wire Fabric
  • Expanded Mesh
  • Laths
• Extrusion is the process of shaping material by forcing it to flow through a shaped opening in a die, with the extruded material emerging as an elongated piece with the same profile as the die opening
• Aluminum panels and sandwich panels are pre-fabricated units, generally manufactured using dimensions of modular and non-modular window-width for building exterior, and in 600mm, 900mm, and 1200mm widths for interior partitions and dividers
• Aluminum Panels and Sandwich Panels

  Panels for the exterior of buildings primarily consist of an aluminum exterior facing which may be an aluminum casting, an extrusion or sheet material which has been pressed, stamped or formed into specially designed shapes
• Sandwich Panel


  A system of construction called skin construction, comprising a cellular core of aluminum or other material with a skin of aluminum applied and bonded to both sides, thereby forming a unified whole in which all the components work as one
• Mechanical finishes for aluminum are obtained by grinding, polishing, scratching, sandblasting, embossing, or other treatment of the surface to achieve a desired effect or to provide a base for other finishes
• Chemical finishes for aluminum are based on chemical reactions with the aluminum surface to achieve etching, cleaning, or polishing of the surface to remove any oxide film or surface irregularity and provide a design, a clean surface texture, or a polished effect, or to oxidize the surface with aluminum
• Types of Metals


  • Aluminum
  • Iron
  • Steel
  • Copper
  • Tin
  • Zinc
  • Brass
  • Bronze
  • Chromium
  • Nickel
  • Lead
• Aluminum


  A lightweight, corrosion-resistant, silvery-white metal
• Types of Aluminum Finishes


  • Mechanical finishes
  • Chemical finishes
  • Electrolytic finishes (anodized)
  • Electroplating
  • Porcelain or Vitreous Enamel
  • Paint
• Mechanical finishes


  Obtained by grinding, polishing, scratching, sandblasting, embossing, or other treatment of the surface to achieve a desired effect or to provide a base for other finishes
• Chemical finishes


  Based on chemical reactions with the aluminum surface to etch, clean, or polish the surface, or to oxidize the surface
• Electrolytic (anodized) finishes


  Protective oxide coating formed on the aluminum surface, can be transparent or opaque, hard, and able to absorb dyes
• Electroplating


  Aluminum can be covered with a protective or decorative film or another metal, usually by electrodeposition
• Porcelain or Vitreous Enamel


  Forms a hard, resistant surface available in a broad color range
• Paint


  Paint, lacquer and enamel can be applied as finishes to aluminum surfaces that have been prepared by a suitable chemical treatment finish
• Iron


  • Tough, malleable silvery-white metal that is soft and ductile, easily magnetized, and readily oxidizes in air
• Pig Iron


  Crude or impure form of iron containing 3-4% carbon and varying amounts of other elements, the starting point for producing other iron and steel
• Cast Iron


  An iron-carbon alloy containing more than 1.7% carbon, poured while molten into forms, too hard and brittle to be shaped by hammering, rolling, or pressing
• Wrought Iron


  Almost pure iron with less than 0.1% carbon, contains 2.5% slag in physical association, soft, malleable, tough, fatigue-resistant, and resistant to progressive corrosion
• Steel


  Alloys of iron and carbon containing up to 2% carbon, made in malleable or ingot form, can be wrought, rolled, cast, and welded but not extruded
• Structural Steel


  Medium carbon steel with controlled carbon content to provide strength and ductility, available in various shapes and forms for construction
• Types of Metals


  • Aluminum
  • Iron
  • Steel
  • Copper
  • Tin
  • Zinc
  • Brass
  • Bronze
  • Chromium
  • Nickel
  • Lead
• Methods of Joining Metals

  • Soldering
  • Brazing
  • Welding
  • Rivets
• Metals for Concrete Reinforcement

  • Steel Bars
  • Wire Fabric
  • Expanded Mesh
  • Laths
• Structural Steel


  Medium carbon steel with its carbon content controlled to give both the strength and ductility necessary for its use
• Structural steel is available in angles, channels, I-beams, H columns, T shapes, Z shapes, plates, round pipe columns, sheet piling, open web joists, and light steel framing shapes
• Wrought Carbon Steels


  Steels to which manganese, silicon, aluminum, titanium, and molybdenum have been added in sufficient quantity to produce properties unobtainable in carbon steels in cast, rolled or heat-treated form
• Alloy Steels


  • Increase the following properties: strength, hardness, ease and depth of hardenability, performance at high or low temperatures, electromagnetic properties, wear resistance, electrical conductivity or resistivity
• High-strength low-alloy steels


  A group of trade name steels with improved mechanical properties and resistance to atmospheric corrosion, used as reinforcing for pre-stressed concrete, high strength bolts, special structural steels and cables for elevators, etc.