Drilling Machine Classification
Industrial drilling machines range from simple bench drills to sophisticated CNC drilling centers with automatic tool changing. Upright drilling machines handle medium to heavy duty work with powered table elevation for height adjustment. Radial drilling machines feature a movable spindle head on a horizontal arm enabling drilling at any position within their radius.
Drill Bit Types and Selection
Twist drill bits are the most common type suitable for general purpose drilling in metals, plastics, and wood materials. Center drills create starting points for larger drills and produce center holes for lathe work between centers. Step drills produce multiple diameter holes in sheet metal while indexable insert drills offer economical large diameter drilling with replaceable edges.
Achieving Precision Holes
For precision holes start with a center drill to establish accurate position then drill undersized leaving material for final reaming. Use peck drilling cycles when creating deep holes to break chips and allow coolant to reach the cutting edges. Reaming provides the best combination of dimensional accuracy and surface finish for close tolerance holes in production.
CNC Drilling Operations
Modern CNC drilling machines integrate automatic tool changers and programmable positioning for high-volume production of parts with multiple hole patterns. These systems can drill, tap, counterbore, and ream in a single setup eliminating secondary operations and reducing cycle time. Programming features like canned cycles simplify complex drilling sequences while maintaining quality.
