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Lathe Tool Tip Types

Turn Tip Types

The tip type (usually represented by a number) expresses the direction and useful paths of travel that a particular tool can cut. Most tips are "pointed" in a particular direction and have a limited angle at which they can cut. (There are no practical omnidirectional cutting tools on a lathe.) The tool tip type indicates which axis/axes you can cut along. The tip type also determines how tool nose compensation is applied. (See Lathe Tool Nose Radius Compensation for more details about compensation.)

In the following diagram, each tool type is shown, with the direction of X and Z where the tool is "pointing" and the cutting direction(s) indicated by the dotted lines.

In this diagram, +Z is to the right, and +X is up (the same as in the previous diagram).

(Image Source: CNC Programming Handbook, 3rd Ed.; Peter Smid; p276)

These diagrams are for a rear-turret lathe. Some diagrams you may find will look (vertically) reversed because they are describing orientations for a front-turret lathe.

Turn Operations and Tip Types

Machinists will frequently associate tip types with types of turning.

  • Turning
    • cutting surface is in the -X direction
    • tip types: 2, 6, 1
  • Boring
    • cutting surface is in the +X direction (i.e. hollowing out the inside of something)
    • tip types: 3, 8, 4
  • Facing
    • cutting surface is in the -Z direction (i.e. removing material from the end, or "face," of the work piece)
    • tip types: 2, 7, 3
  • Back Facing
    • cutting surface is in the +Z direction (i.e. removing material from an "inside face" of a part)
    • tip types: 1, 5, 4