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NIJ, Firearm's Examiner Course, Module 13, retrieved May 1 2020 ,https…

- - - - Types of Metal Chips
        
        Continuous Chips: long ribbons of metal found in machining a ductile metal with a sharp cutting tool.
        
        Discontinuous Chips: segmented chips that are broken up into particles which are associated with brittle metals and a coarser result.
        
        Continuous Chips with built-up edge: accumulate tiny particles that weld to the piece which produces a coarser surface on the piece.
        
        Fineness/Coarseness Variability:
        
        Brittleness or ductility of piece
        
        Quality of cutting tool
        
        Adjustment of cutting tool for the depth of the cut
        
        Sharpness of tool
        
        Speed at which piece moves to tool (Feed Rate)
        
        Angle of cutting tool
        
        Speed of tool
        
        Condition of the edge of tool
        
        Temperature of piece and tool
      - Lathe Operations: those in which the exterior of the piece rotates against a tool.
        
        Turning: rotates exterior of piece against single-point tool
        
        Facing: Tool is used on surfaces perpendicular to rotating spindle
        
        Boring: a single-point tool enlarges a hole beyond capability of a drill or reamer and works the interior of piece
      - Milling Operations: involves use of rotating multi-toothed cutters moved into piece which allows for wide variety of cutting.
        
        Face milling: surface of piece is parallel to cutter located at end of spindle. Cutters are located on face and edge of rotating cutter.
        
        Peripheral Milling: surface being machined is parallel to cutting teeth in periphery of tool.
        
        End milling: fluted cutting edges are arrange on circumference and end of rotating shaft vertical to piece. The cutting teeth are found on the end of the cutting and circumference of the cutter body.
        Distinct Methods:
        
        Conventional/Up-Milling: piece fed against cutting teeth
        
        Climb/Down-Milling: piece is fed in same direction as teeth
      - Other Cutting Operations:
        
        Shaping: single-point machine cuts in straight line by repeated parallel strokes
        
        Planing: piece moves under stationary cutting tool
        
        Drilling: cylindrical cutting tool with multiple fluted cutting edges arrayed in spiral
        
        Reaming: cutting technique that it is sometimes used after drilling
        
        Broaching: multitooth cutting tool that moves against piece.
        
        Sawing: multitoothed tool in which the edges are arranged in line.
        
        Filing: material is formed/removed using teeth that are shallow and broad.
        
        Abrasive Machining: Thousands of tiny edges made up of individual abrasive grains and used as a finishing operations.
  - - - Electrical Discharge Machining (EDM): tool and piece are oppositely charges with nonconductive dielectric fluid. A spark arcs across fluid to piece which melts surface.
        Laser Machining: optical focusing of a laser beam to vaporize metal
      - Electrochemical Machining (ECM): Electrically conductive fluid and direct current to remove material (reverse of traditional electroplating)
        Chemical Machining (Etching): masking/protecting areas not to be machined then exposing remaining areas to chemical etchant.
        Hydrodynamic Machining: water jet combined with abrasives that can cut complex patterns without generation of heat.
      - Ultrasonic Machining: technique that combines ultrasonic sound waves with a slurry of abrasive material for the controlled machining of a surface.
        Electron Beam Machine (EBM) requires a vacuum and shielding due to X-rays