HHS® Tube
helical hollow strand

HHS® Tube, or Helical Hollow Strand, is best described as a strand with an open center working channel. While HHS® has proven to be useful in many applications, it is most often utilized to transmit torque or pushing forces due to its exceptional whip free characteristics and a high resistance to kinks. HHS® tube can be manufactured in single, double, and triple layers in order to provide varying flexibility and control. Please contact us with your specifications – we’ll help you design a HHS® tube that fits your exact needs.

  • Over the wire device
  • Manipulation components
  • Working channels
  • Endovascular devices
  • Minimally invasive tools
  • Catheter devices
  • Delivery devices
  • Urological tools
  • Neurological components
  • Bioconductors

We design HHS® Tube using solid modeling according to mathematical formulas.  Using parametric design, we can evaluate many design considerations in a short time.  Materials are normally spring temper, however, Nitinol is provided in the superelastic condition.  Properties will be influenced by any of the following design variables:

  • Inside Diameter: 0.001 (0.0254 mm) to 0.130” (3.302 mm)
  • Outside Diameter: 0.0025" (0.0635 mm) to 0.160" (4.064 mm)
  • Filars: 6- 18
  • Layers*: 1-3
  • Lengths*: 1”-10' (25 mm – 3 m)
  • Pitch: left, right, unidirectional, reverse

*If you have a request that is outside of these specifications, please contact us.

Characteristics HHS
Unifilar Multifilar
Torque Excellent Poor Good
Windup (Low) Good Poor Poor
Whip Excellent Excellent Excellent
Pushability Excellent Excellent Good
Use Tension Excellent Poor Good
Compression (%) Good Excellent Poor
Hoop Strength Good Excellent (Tight Wound) Good
Wall Thickness (thinwall) Good Excellent Excellent
Secondary Operations:
  • Customer specified performance testing
  • Droop, compression, yield (elongation at load) or torque
  • Square cut ends
  • Welding
  • Taper ground
  • Chamfering
  • OD step grinding
  • Coating
  • Assembly
  • Formed HHS®
  • Soldering
  • Velocity™

While other alloys may be available for use in your HHS® tube, these are the most prevalent: