Kop-Flex Floating Shafting



The KD4 Coupling is designed for medium and heavy duty applications. It only requires angular misalignment capacity as in the case of a three bearing installation of floating shaft arrangements. For complete floating shaft assemblies, consider a KD41. A KD41 uses two single KD4 flex halves in conjunction with a solid center shaft. KD42 designed as a drop-in replacement to gear coupling floating shafts. For lighter weight or higher stiffness, a tubular floating shaft is available.

With floating shafting for gear couplings, an unsupported floating shaft is used to span the gap between the driving and driven shafts. This is when the shafts are widely separated. The two couplings required at each end of that shaft consist of one half of a standard coupling bolted to a rigid hub. Each unit is called a Flex-Rigid Coupling. Usually the rigid hubs are mounted on the driving and driven shafts. This is so that the flex halves on the floating shaft may be replaced without disturbing the connected equipment.

KD Series


  • Sizes 103 – 905
  • Heavy duty applications
  • Designed for applications requiring angular misalignment only
    • Three bearing system or floating shaft arrangements
    • Drop-out unitized disc packs
    • Used on KD41 & KD42 couplings


  • Sizes 103 – 905
  • Max. bore up to 13.5″
  • Heavy duty applications
  • Drop-out unitized disc packs
  • Economical solid or tubular floating shafts
  • KD42 designed for direct gear coupling replacement


  • Standard KD disc coupling style
  • Tele​scopic / slide design with off-the-shelf slides
  • Can fit several shaft separation with one



  • 300% greater lube capacity
  • All-metal end rings
  • 2 to 3 times the life vs. o-ring style
  • 6″ (152 mm) to 78″ (2 m) OD
  • Max. bore up to 36″ (914 mm)
  • Coupling of choice with longest history
  • Custom-design and specials available see catalog


  • O-ring style seal
  • Half for half interchangeable with all AGMA standard couplings
  • Max. bore up to 43.5″ (1.1 meter)
  • Max. torque up to 284 million lb-in (32100 kN-m)
  • Slide, shear pin, floating shaft, alloy steel, and other styles available
  • Custom design and specials available – see catalog


  • High misalignment seal to prevent grease leakage
  • Greater tooth contact than other spherical styles
  • 40° tooth
  • Max. bore up to 9.25″ (235 mm)