Kop-Flex Model B Gear Couplings



The Model B coupling is an all-metal end ring design. It is a configuration that is smaller in size and lighter in weight than the FAST’S® coupling. At the same time, it maintains maximum bore capacities. These couplings are manufactured from the same materials as the larger, heavier FAST’S type. They are also held to the same quality standards. The Model B end ring provides a permanent seal and permits a compact design. Each sleeve has a Type UD lube plug permitting assembly at 180° apart to facilitate lubrication.

When properly installed and lubricated the Model B coupling should require little maintenance. Under most conditions the lubricant reservoir is adequate to allow continuous operation for a year or more. All flange bolt holes are precision drilled to assure flange piloting and interchangeability. Model B bolts are special with respect to body length, thread length and bolt tolerance.


  • Exposed bolt and shrouded bolt configurations
  • Misalignment capability up to ½ o per gear mesh
  • An all metal end-ring is contoured to provide an internal lubricant retention dam. This is used to pilot the sleeve in respect to the hub.
  • Size range: 1 – 3 /12; up to 3.75 in. bore capacity.
  • Torque range: up to 117, 000 lb-in torque
  • Full-flex, flex-rigid available with spacers
  • Flange not interchangeable with other type of gear couplings
  • Close fitting, tight to tolerance flange bolts and bolt holes
  • Lube capacity less than FAST’S but more than “O-ring” style—grease lube only

Features & Benefits:

  • Less frequently required lubrication
    • Minimized downtime from failure to lubricate
    • Savings on lubrication and labor costs
  • Smaller and lighter than FAST’S coupling, but with the same maximum bore capacities
  • Tight tolerance flange bolt holes
    • Minimized bolt and bolt hole failures
  • No soft seals to fail or replace
    • Lubricant level maintained above the gear teeth
    • Less wear or rusted teeth
  • Less concentration of tooth loading
    • Less premature tooth wear
  • Highly featured coupling at standard coupling price
    • Lower cost alternative to the FAST’S coupling
    • Available in distributor and warehouse stocks worldwide