Four types of elastomer designs and materials are offered to allow for flexibility in addressing specific application requirements.


Standard Materials:

  • NBR (Nitrile Butadiene Rubber) — Buna N (Black)
    • Considered the standard and most economical for jaw coupling spiders
    • Offers the best combination of temperature and chemical resistance, misalignment, and dampening ability
    • Only material suitable for reciprocating engine applications
    • 80A Shore Hardness except  L035=60A
    • Temperature Range – 40° F to 212° F (-40° C to 100° C)
    • Resembles natural rubber in resilience and elasticity


  • Urethane (Blue)
    • Greater torque capability than NBR (1.5 times), provides less dampening effect and operates in a smaller temperature range
    • Good resistance to oil and chemicals
    • Not recommended for cyclic or start/stop applications
    • L050 to L110 Shore Hardness 55D, L150 to L225 Shore Hardness 90-95A
    • Temperature Range -30° F to 160° F (-34° C to 71° C)


  • Hytrel (Tan)
    • Flexible elastomer designed for high torque and high temperature operations
    • Excellent resistance to oil and chemicals
    • Not recommended for cyclic or start/stop applications
    • 55D Shore Hardness
    • Temperature Range -60° F to 250° F (-51° C to 121° C)


  • Bronze
    • Rigid, porous oil-impregnated metal insert exclusively for low speed (max 250 RPM) applications requiring high torque capabilities
    • Not affected by extreme temperatures, water, oil, or dirt
    • Temperature Range -40° F to 450° F (-40° C to 232° C)


Standard Styles:

  • Solid Center
    • Commonly used when shafts of the driver and driven equipment can be kept separate by a standard gap
  • Open Center
    • Allows for the shafts of the driver and driven to be positioned within a short distance
    • Offer shaft positioning flexibility but have a lower RPM capacity (1,750 RPM Max for NBR, 3,600 Max for Urethane/Hytrel)
  • Snap Wrap Flexible
    • Design allows for easy removal of the spider without moving the hubs
    • Allows for close shaft separation all the way up to the hubs maximum bore
    • Maximum RPM is 1,750 RPM with the retaining ring, but if used with the LC Type (with collar) the normal RPM rating of the coupling applies
    • Style is available in NBR and Urethane only, and in limited sizes
  • Cushions
    • Used exclusively for the C Type couplings
    • Load cushions are held in place radially by a steel collar which is attached to one of the hubs