Railko's NF21 and NF22 bearing materials are non-metallic composites which have been specially designed to cope with extreme operating conditions such as high loads, speeds, temperature fluctuations and dirty conditions.

Depending on the application and grade, these thermosetting resin laminates can operate dry, partially lubricated or fully lubricated in oil or seawater.

Railko's marine bearings are approved by all major marine classifications and Navies worldwide.

They offer significant advantages in terms of  reduced maintenance, improved reliability and life of the shaft material.

Applications include

  • Propeller shaft bearings
  • Rudder bearings
  • Steering gear and deck
  • Machinery bushes in both surface and submarine vessels

Tests carried out in sand laden seawater show that Railko NF grades offer greater wear resistance than alternative materials. In addition to this they provide smoother running, reduced noise and prevent stick slip. 


Property Unit of measure Value
Tensile StrengthMpa
Elongation at Break%
Modulus of ElasticityMPa
Impact Strengthkj/m²
Compressive StrengthMPa220
Shear StrengthMPa41
Shore HardnessD Scale
Co-efficient of Frictionμ
Water Absorption @ 23 Deg C%<1
Service Temperature IntermittentᵒC
Service Temperature ContinuousᵒC120
Melting pointᵒC
Thermal ConductivityW/m.ᵒC
Dielectric StrengthkV/mm
Volume ResistivityΩ.cm
Surface Resistivity
Arc ResistanceSec