Steel

Plentiful: Steel is widely available, making it a reliable building material.
Inexpensive: Compared to other construction materials, steel is cost-effective.
Light in Proportion to Strength: Steel offers a high strength-to-weight ratio, allowing for lighter structures with fewer materials.
Suited for Rapid Construction: Steel components are often prefabricated in factories, which speeds up the construction process.

Iron Bridge: First all-metal structure made of cast iron.
Crystal Palace (1851): Built in London using cast iron, showcasing steel's potential in architecture.
Bessemer Process (Mid-1850s): Revolutionized steel production making it faster and stronger.
Open-Hearth Method (1868): A developed steel-making technique in England improving quality.
Eiffel Tower (1889): Constructed using wrought iron and steel; a pivotal moment in steel construction history.
Skyscrapers in the US: Early skyscrapers, like the Home Insurance Building (built after the 1871 Chicago fire), paved the way for urban architecture.

Mini-Mills Production: Almost all steel in the US is produced in mini-mills from scrap steel utilizing electric arc furnaces.

World Production (2024): 1,881.4 million metric tons.
- China: 1,005.1 million tons (1st)
- India: 149.6 million tons (2nd)
- Japan: 84.0 million tons (3rd)
- United States: 79.4 million tons (4th)
- Russia: 70.7 million tons (5th)
- South Korea: 63.5 million tons (6th)
- And further down to countries like Mexico (13.7 million tons) and others.

Home Insurance Building: First modern skyscraper, demonstrating the potential of steel structure.
Flat Iron Building: Recognizable for its triangular shape, it showcases innovative steel framing.
Empire State Building: Iconic skyscraper highlighting the use of steel in high-rise construction.
Chrysler Building: An art deco skyscraper known for its striking design and steel framework.
Brooklyn Bridge: An engineering feat with its steel cables and structural design.
Beijing National Stadium: Known as the Bird's Nest, it features a unique steel structure.
Seagram Building: A prime example of modernist architecture made from steel and glass.
Gateway Arch: An iconic symbol of St. Louis, made predominantly from stainless steel.
Burj Khalifa: Currently the tallest building in the world, utilizing a vast amount of steel in its structure.
Eiffel Tower: A historic landmark made of wrought iron, a critical point in steel construction history.
Sydney Harbour Bridge: A massive steel arch bridge known for its engineering and design.
Willis Tower (formerly Sears Tower): A landmark skyscraper employing steel in its design.
Investcorp Building: Contemporary building showcasing modern design with steel components.
The Shun Hing Square Tower: Noted for its unique architecture using steel.
Museum of Contemporary Art, Cleveland: Features innovative steel use in its design.

Wide Flange: Denoted as Nominal depth x weight (e.g., W21x83).
Channel: Expressed as Nominal depth x weight (e.g., MC10x36).
American Standard Channel: Also expressed as Nominal depth x weight (e.g., C6x13).
American Standard Beam: Represented as Nominal depth x weight (e.g., S18x70).
Angle: Defined by length of each leg followed by thickness (e.g., L4x3x3/8).

Rivets: Rarely used in modern construction.
Bolts: Commonly used for joining steel components.
Types of Connections:
- Bearing-type
- Slip-critical
- Turn-of-nut method
- Direct tension indicator
- Calibrated wrench method
- Tension control bolts
- Swedge bolts
Welding: Considered stronger than the members they join, widely used in steel construction.

Properties: An alloy that develops a protective deep brown oxide coating to prevent further corrosion, making it suitable for outdoor use in architecture.