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Term
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Definition
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| Galvanized |
Zinc plated or coated steel. |
| Galvanized Steel |
Steel coated with a thin layer of zinc to provide corrosion resistance in underbody auto parts, garbage cans, storage tanks, or fencing wire. Sheet steel normally must be cold-rolled prior to the galvanizing stage.
Hot-Dipped. Steel is run through a molten zinc coating bath, followed by an air stream "wipe" that controls the thickness of the zinc finish.
Electrogalvanized. Zinc plating process whereby the molecules on the positively charged zinc anode attach to the negatively charged sheet steel. The thickness of the zinc coating is readily controlled. By increasing the electric charge or slowing the speed of the steel through the plating area, the coating will thicken.
Differences. Electrogalvanizing equipment is more expensive to build and to operate than hot dipped, but it gives the steelmaker more precise control over the weight of the zinc coating. The automotive manuacturers, because they need the superior welding, forming and painting ability of electrogalvanized steel, purchase 90% of all tonnage produced. |
| Gate |
In casting into molds, molten metal is poured into the gate (where the metal enters the casting), then enters the space provided by the removed pattern. (Also see "Riser" and "Sprue.")
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| Gauge |
The thickness of steel sheet. Better-quality steel has a consistent gauge to prevent weak spots or deformation. |
| Gauging |
A method of determining the weight of material loaded into barges, ships, and other vessels that travel in the water. Basically figured by determining the number of feet the vessel sinks into the water before and after material has been loaded. The density of the material times the displacement will approximate the weight of the material.
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| Gondola Car |
A railroad car with the general appearance of a rectangular, topless, box of wheels. |
| Grade |
A name given to a class of material prepared and sorted to conform to certain specifications. Grade will often include chemical as well as physical requirements, and may also specify the method used to prepare the material (i.e., baled, shredded, etc.). |
| Granulator |
A machine for shredding small materials such as plastics. |
| Graphite |
Elemental carbon in cast iron.
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| Gray Iron |
A ferrous material containing 2-4% carbon, 1-3% silicon with the graphite in flake form. (Appears as corn flakes in Jell-O.)
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