Drejninger

Drejninger is the Danish plural form of drejning, a term used to describe turning or rotation. The concept appears in several fields, referring to both the act of turning and the resulting orientation or shape.

In mathematics and physics, a drejning denotes a rotation of an object around an axis. In two dimensions it corresponds to turning by a specific angle, typically measured in degrees or radians. In three dimensions, a drejning can be described by rotation matrices, quaternions, or other representations that preserve distances and orientations of objects.

In engineering and manufacturing, drejning commonly refers to turning on a lathe. During turning, a workpiece is rotated while a cutting tool removes material to produce cylindrical or conical shapes. Types of turning include external turning, internal turning, facing, taper turning, and thread turning. Key parameters are cutting speed, feed rate, and depth of cut, and operations may be performed on conventional lathes or computer numerical control (CNC) machines. Precision and surface finish depend on tooling, machine stability, lubrication, and cutting conditions.

In navigation and transportation, drejninger describes a change of direction or a turning maneuver. This can apply to driving, aviation, maritime operations, and other contexts where an entity alters its heading or path.

Across domains, drejninger thus encompasses both the geometric notion of rotation and the practical processes of turning parts or changing direction.