8th Grade Agriculture

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• 8th Grade Agriculture
• Dan Hill

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Why is metal important?

• Form much of the structures in the world around
  us.
• Skyscrapers became a reality because of
  structural steel.
• Transportation industry depends on metal.
• High tech machinery need metal.
• Most all machines and equipment are made from
  metal.

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Classifications of Metal

• Ferrous
• Fe
• Made from Iron Ore
• Nonferrous
• Do not contain Iron
• Alloy
• Combination of two or more metals

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Identifying Metals

• Magnetic Test
• Contains Iron will be attracted to magnet
• Spark Test
• Iron will give off spark
• Different types of iron gives off different types
  of sparks

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Metal Terminology

• Malleable
• Workable
• Ductile
• Bend slightly without breaking
• Anneal
• Heat and slowly cool
• Softens and toughens
• Tempering
• Process of reheating and cooling after it has
  been bent
• Hard, Tough not easily bent

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Ferrous Metals

• Cast Iron
• Grainy and not easily shaped or bent
  (non-malleable)
• Melted and poured into molds called casting.
• Will break before it will bend
• Machinery parts and engine blocks

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Ferrous Metals

• Wrought Iron
• Almost pure iron
• Very Malleable
• Resists Rust
• Fences and other ornamental uses

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Ferrous Metals

• Mild Steel
• The workhorse of metals
• Made by adding small amounts of carbon with iron
• Tough, strong, ductile and malleable
• Rolled into many different shapes
• Used extensively in the ag mechanic shop

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Mild Steel Shapes

• Rod
• Sized by Diameter
• 20 foot lengths
• Flat
• Sized by thickness and width
• 20 foot lengths
• Angle
• Sized by outside measurements of each leg and
  thickness
• Even or Uneven
• 20 foot lengths

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Mild Steel Shapes

• Channel Iron
• Sized by width of outside and weight per foot
• 20 foot lengths
• Square Tubing
• Sized by outside dimensions and thickness
• 24 foot lengths
• Rectangular
• Sized by outside dimensions and thickness
• 24 foot lengths
• Pipe

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Mild Steel Shapes

• Pipe
• Sized by inside diameter
• 21 foot lengths
• Schedule 40 standard thickness
• Schedule 80 double standard thickness
• I-Beam
• Sized by thickness and Height of I
• H-Beam
• Sized by thickness and Height and Width of H
• Tee
• Sized by thickness and Height of T

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Mild Steel Shapes

• Sheet Metal
• Plate
• Sized by thickness 4 foot by 8 foot
• Flat on both sides
• Tread Plate
• Sized by thickness 4 foot by 8 foot
• Expanded Metal
• Sized by thickness and size of opening 4 foot
  by 8 foot
• Either raised or flattened

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Ferrous Metals

• Tool Steel
• Contains a specific amount of carbon which
  permits it to be hardened
• Can be annealed (heat then slowly cool which
  softens and toughens steel)
• Tempered controlled reheating and cooling of
  steel after it has been shaped.

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Ferrous Metal

• Stainless Steel
• Made by adding nickel and chromium to steel
• Tough, will not rust, resists corrosion
• Used extensively in the food industry

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Ferrous Metals

• Plated Steel
• Tin old method of coating metal
• Zinc galvanized steel
• Vapors are hazardous to breath