machining

machining

1. Types of Machining

   • Lathe/Turning, Milling, Drilling, Shaping/Planing

2. Cutting Tools

   • Single Point- one cutting edge e.g lathe cutting tools
     • Multi Point- multiple cutting edges e.g saw blades
       • Desirable Properties of Cutting Tools
         • Harder than the material they cut
           • Need to be available in a wide variety of shapes to suit different materials
         • Able to withstand heat and keep their cutting edge
           • Need to be easily sharpened
         • Conduct heat away
           • Need to be tough
   • Cutting Speeds and Feeds
     • Speed: the speed the tool moves against the surface of the work material
       • Feed: the speed at which the cutting tool is advanced through the workpiece
         • Chip Formation
           • Discontinuous Chip: very short broken off pieces that occurs in hard brittle materials e.g brass?cast iron
             • Continuous Chip: long strips that occurs in ductile materials e.g aluminium/mild steel
               • Continuous With Built Up Edge: waste material welds to the face of the cutting tool. Can happen in ductile materials e.g aluminium/mild steel if machine parameters are not correct