• axial deflection
  • axial offset. helical
  • helicity
  • Helix
  • screw
  • spiral
  • spiral-shaped
  • Torsion
  • torsional stress
  • twist
  • twisting

Helicity, also commonly referred to as torsion or twisting, is understood to be a curvature course adopted by wire radially rather than axially upon leaving the curvature plane. Such a curvature course can be intentional, as in the production of rope and cable where it is called the lay length, and in the production of springs where it is called the pitch.

Helicity is an undesirable condition for all follow-up processes if it is not specifically created for the product but arises unintentionally due to certain production factors. Frequent causes of helicity include overhead pulling off, static unwinding and unspooling, incorrect deflecting, frequent changes of direction, and any faulty process transitions with a negative effect on round material which rotates during processing.

Inconstant or indeed alternating helicities not only impede the process flow but also rule out final products of any required constancy.

Aids such as helix straighteners, killing-straighteners and additional straightening systems can go a long way in solving the problem. Above all, however, it is important to avoid the avoidable and to create a constant process.

Helix straightener

  • height-adjustable straightening roll
  • helix straightening

A wire wound into a coil or onto a spool should have only one curvature - that of the spool or coil - in one plane if the follow-up process is to proceed without difficulty. Changing preliminary processes with sometimes inconstant process transitions create helicities, i.e. twisting, in the wire.

Helicities need to be avoided or, where constant helicities are concerned, eliminated by means of a helix straightener. A helix straightener can produce as well as remove helicities.

Like a standard straightener, a helix straightener has several straightening rolls which are partly or fully arranged in familiar manner so that they can be adjusted relative to each other.

In addition to this, one or more straightening rolls can be adjusted in height. The groove of the height-adjusted straightening roll thus forces the wire unilaterally from its zero line, bending it with unequal flank pressure into a second curvature plane. Helicities are thus removed or created by force-feeding the wire through these adjustable positions.