Newly Re-designed P-Series Gearbox improves Backlash, Corrosion Resistance and Center Distance between Input and Outputs! 

Double Loop Couplings

Double loop couplings, also known as a "Crazy Eight Couplings," “Twisted Eight Couplings,” or “K Couplings,” are two-stage couplings that feature a flexible, elastomeric dual loop element to handle angular, radial, and axial misalignment. K couplings are typically used to transmit rotation in small drives that do not require high precision or precise tolerances. Read our White Paper, “How to Select Shaft Couplings”, for assistance with selecting the appropriate shaft to shaft coupling for your application. Couple to almost any shaft diameter with our Bore Reducers or attach your coupling to an Ondrives.US Precision Ground Shaft, available from stock.


K Couplings Provide Flexibility in Three Misalignment Modes

Ondrives.US Hytrel™ Double Loop Drive Couplings provide exceptional flexibility in angular, radial, and axial modes and work without any friction, wear, or noise. These crazy 8 couplings perform well in small drive applications and are an ideal, safer, and longer-lasting component upgrade for traditional (pre-encoder) elevator applications.
Our flexible shaft couplings are made with DuPont’s Hytrel™ material, substantially improving the performance characteristics over competitors K couplings. The Hytrel™ flex member is permanently swaged to steel or stainless-steel hubs producing a compact, robust, and highly flexible misalignment shaft coupling.

Typical applications for double loop couplings include:

  • Encoders
  • Light power drives
  • Small generators
  • Small pumps
  • Stepper and servo motors

The Ondrives.US Advantage: The world's best Double Loop Shaft Couplings

Our flexible shaft couplers provide 32% to 120% more torque than other twisted 8 couplings and are available with inch and metric bores. Additional features and benefits include:
  • High torsional rigidity
  • Torques to 160 in-lbs.
  • Outstanding resistance to acids, alkalis, solvents, oils, grease, and ozone
  • Operating temperature range:  -40°F to +212°F (-40°C to +100°C)
  • Dampening of vibration and shock
  • Corrosion protection with our stainless hub series
  • Mixed metric and inch and other bores on request
  • Maximum speed: 3,000 RPM
  • Hubs: Zinc plated steel or 300 series Stainless Steel
  • Tough and durable Hytrel™ flex member
  • Up to 15° angular misalignment
  • Up to .130" radial misalignment
  • Up to .43" axial misalignment
  • High tear resistance
  • Any bore to bore combination available within the min. max. limit
  • Electrically Isolating

Learn More About Our Standard and Custom K Couplings for Shaft Misalignment

Ondrives.US carries a wide selection of inch or metric twisted eight couplings and other components for shaft misalignment. We also offer customization and modification for our double loop shaft couplings.
Request a quote for customized couplings or contact our application engineers to discuss your needs.

Hytrel™ is a trademark of DuPont