END MILL SELECTION BASICS
- END MILLS have cutting teeth on both end and side, permitting end cutting and peripheral cutting. Center cutting types permit plunge and traverse milling.
- CUTTING EDGE: Select sharp edged for faster speeds. Select radial edged for longer tool life.
- SHANK DIAMETER: Select largest diameter available to maximize rigidity and minimize axial deflection and chatter.
- NUMBER OF FLUTES: Select fewer flutes for milling softer materials at higher speeds and feeds where more chip space is required or when machine horsepower is limited.
- Select more flutes for milling tougher materials at reduced speeds and feeds or for increased table feeds using the same cutting speeds.
- CUTTING DIAMETER: Select largest practical diameter to maximize rigidity, minimize chatter and improve tool life. If machine spindle speed is limited, the largest practical diameter permits higher cutting speeds.
- FLUTE AXIAL RELATIONSHIP: Select straight flutes for usual general purpose.
- Select right spiral flutes for improved cutting action and easier chip removal.
- Select left spiral flutes for use in absorbing impact shock when entering steel work piece maintains constant hold down pressure, and minimizes chatter.
- Select high spiral (15° or more) to dramatically improve cutting action, finish, chip removal and tool life. High spirals distribute impact load more evenly throughout the tool’s entire revolution.