What is turning?

  • (noun): A movement in a new direction.
    Example: "The turning of the wind"
    Synonyms: turn
    See also — Additional definitions below


Turning is a machining process in which a cutting tool, typically a non-rotary tool bit, describes a helical toolpath by moving more or less linearly while the workpiece rotates. The tool's axes of movement may be literally a straight line, or they may be along some set of curves or angles, but they are essentially linear (in the nonmathematical sense). Usually the term "turning" is reserved for the generation of external surfaces by this cutting action, whereas this same essential cutting action when applied to internal surfaces (that is, holes, of one kind or another) is called "boring". Thus the phrase "turning and boring" categorizes the larger family of (essentially similar) processes. The cutting of faces on the workpiece (that is, surfaces perpendicular to its rotating axis), whether with a turning or boring tool, is called "facing", and may be lumped into either category as a subset.

Read more about Turning.

Some articles on turning:

Dynamics of Turning - Speeds and Feeds
... Speeds and feeds for turning are chosen based on cutter material, workpiece material, setup rigidity, machine tool rigidity and spindle power, coolant choice, and other factors ...

More definitions of "turning":

  • (noun): The act of changing or reversing the direction of the course.
    Synonyms: turn
  • (noun): Act of changing in practice or custom.
    Example: "The law took many turnings over the years"

Famous quotes containing the word turning:

    Many people operate under the assumption that since parenting is a natural adult function, we should instinctively know how to do it—and do it well. The truth is, effective parenting requires study and practice like any other skilled profession. Who would even consider turning an untrained surgeon loose in an operating room? Yet we “operate” on our children every day.
    Louise Hart (20th century)

    Like dreaming, reading performs the prodigious task of carrying us off to other worlds. But reading is not dreaming because books, unlike dreams, are subject to our will: they envelop us in alternative realities only because we give them explicit permission to do so. Books are the dreams we would most like to have, and, like dreams, they have the power to change consciousness, turning sadness to laughter and anxious introspection to the relaxed contemplation of some other time and place.
    Victor Null, South African educator, psychologist. Lost in a Book: The Psychology of Reading for Pleasure, introduction, Yale University Press (1988)

    Great is your faithfulness, O God, Creator,
    with you no shadow of turning we see.
    You do not change, your compassions they fail not;
    all of your goodness forever will be.
    Thomas O. Chisholm (1866–1960)