counterbores
Recessed screw seats
Counterbores are cylindrical flat-bottomed holes that widen the top of a smaller hole, allowing a bolt head or fastener to sit flush with or below the surface.
The tool that creates such holes is also called a counterbore.
The machinist drilled counterbores for the socket head cap screws.
Compare with countersinks, which are conical rather than flat-bottomed.
Hole-making by rotation
- reamingEnlarging or finishing holes
- millingProcessing grain mechanically
- pilotingControlling a vehicle's course
- deburringRemoving machining imperfections
chamfering · spindle · lathe · router · feed · speeds · coolant · workpiece
Hole-boring device
- reamerHole-enlarging cutting tool
- pilotOne who steers aircraft
- cutterOne who severs
- flutesTubular wind instruments
carbide · toolholder · chamfer · cutting · plunge · helix · shank · tip
Distance across through center
- depthDistance below surface
- toleranceWillingness to accept difference
- perpendicularityNinety-degree intersection quality
- accuracyDegree of correctness
measurement · gauge · micrometer · calibration · clearance · interference · finish · roundness
drilling
Hole-making by rotation
- reamingEnlarging or finishing holes
- millingProcessing grain mechanically
- pilotingControlling a vehicle's course
deburring · chamfering · spindle · lathe · router · feed · speeds · coolant · workpiece · fixture
drill
Hole-boring device
flutes · carbide · toolholder · chamfer · cutting · plunge · helix · shank · tip · coating
diameter
Distance across through center
- depthDistance below surface
- toleranceWillingness to accept difference
- perpendicularityNinety-degree intersection quality
accuracy · measurement · gauge · micrometer · calibration · clearance · interference · finish · roundness
bolt
Threaded rod for nuts