DRILLING OPERATIONS

• Boring Operation


  1. Enlarge a hole by means of an adjustable cutting tool with only one cutting edge

  2. Used to finish a hole accurately and to bring it to the required size

  3. To machine the internal surface or a hole already produced in casting

  4. Used to correct out of roundness of the hole

  5. To correct the location of the hole
• Counterboring Operation


  Enlarging the end of a hole cylindrically
• Countersinking Operation


  A cone-shaped enlargement of the end of a hole
• Drilling Operation


  One of the simplest methods of producing a hole
• Lapping Operation


  Sizing and finishing a small diameter hole
• Reaming Operation


  1. In order to finish a hole and to bring it to the accurate size

  2. Reamer has multiple cutting edges
• Spot Facing Operation


  Smoothing and squaring the surface around a hole
• Tapping Operation


  1. Combines drilling and tapping in one process to create threaded holes

  2. The tap is rotated and advanced into the pre-drilled hole to gradually cut the threads
• Trepanning Operation


  Producing a hole by removing metal along the circumference of a hollow cutting tool