Counter Bore

Spot Facing – Provides a true bearing surface for a washer.

Counter boring – Provides a recess for a bolt head, bushing or pin.

Tool construction

Similar to an end mill, cuts on the end.

Different from an end mill in that there is no cutting edge on the outside diameter.

Normally spiral angle of 15 degrees. Brass requires straight flutes.

Rotary table

Adding another axis to the mill

Speeds production of hole patters

Allows milling of curves, pockets, channels where not easily done otherwise.

Horizontal

Vertical

Fixture

Fixture Plate Chuck Toe clamp

Part Location

Co Axial indicator (Co-ax indicator)

Simple means of center locating in round parts.

May be run at LOW speeds when indicating

Process

Deck part using mill and rotary table Locate center C- bore to depth of .250