Common Metal Forming Technique
(Tool mark Identification)
1. Forging - The shape metal while hot and plastic by hammering or by a forging process,either by hand or by machine. 2. Casting - An object at or near finished shape which is produced by solidification of a substance in a mold.Pouring molten metal into a mold to produce an object of desired shape. 3. Blanking - Cutting or pressing a piece of metal from a sheet.In ammunition manufacture,the usable part of a blanking operation is the material removed from the hole,usually a disk. 4. Shearing - To cut sheet or bar metal between two blades which pass immediately to each other. 5. Stamping - To cut out,bend or form with a stamp or die. 6. Drawing - A process using dies and punches to simultaneously reduce the diameter and extend the length of a cup-shaped metal part.Used for both cartridge cases and bullet jackets . 7. Hammer forging - (Swagging) or (barrel swagging) The process of forming the interior and/or exterior shape of the barrel of a firearm by hammering. 8. Extrusion - The slow forcing of material under high pressure through a die reduce its diameter.This process is generally performed in a hydraulic press. Lead wire used in bullet making is extruded.Impact extrusion can be used to make bullet jackets and cartridge cases. |
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