helix

A curve on the surface of a cylinder or cone such that its angle to a plane perpendicular to the axis is constant; the three-dimensional curve seen in a screw or a spiral staircase.

A small volute under the abacus of a Corinthian capital.

The incurved rim of the external ear.

• helix piercing

An upside down midair 360° spin in playboating.

To form or cause to form a helix.

• A large positive inclination gives a chip which will helix out of the space between the face mill and the workpiece.
• When the shaft is unsupported, the large torque tends to helix the inner core, and if the casing is not stiff enough, it will helix the casing also.