Feroform PR18

The Feroform range of materials has been developed by Tenmat to offer the design engineer the chance of replacing metal-based materials with unique, non-asbestos, wearing and bearing composites capable of duplicating and, in some cases, exceeding the performance of asbestos composites. Feroform materials possess strength, durability dimensional stability and excellent wear characteristics besides exhibiting good resistance to attack by many chemicals.

The resins used have been selected for their good mechanical properties and high thermal and dimensional stability. Both organic and synthetic fibres employed for reinforcement of the resins have been selected from the many types available for their high modulus and stability in water and various chemicals.

The “F” Grade range is primarily used in dry applications whilst the “T” & “PR” Grades have been specifically designed with very low water and moisture absorption, making them ideal for use in submerged applications yet still suitable to use dry.

The addition of selected friction modifiers, such as PTFE, graphite and molybdenum disulphide, enhances the wear properties and life of the materials, enabling them to be operated at higher speeds and loads.


Impregnated with PTFE throughout its structure, PR18 has the lowest coefficient of friction of all Feroform PR grades, and this also helps minimize counterface material wear. This grade was once more commonly known as Railko RG22 but since Tenmat’s acquisition of the Railko company and to fit in with the existing Feroform range it has been rebranded as PR18. Designed in response to market demands for a cost effective solution to rudder bearing applications, Feroform PR18 is now approved by all the major marine classification societies.


Property Unit of measure Value
Tensile StrengthMpa90
Elongation at Break%
Modulus of ElasticityMPa
Impact Strengthkj/m²40
Compressive StrengthMPa300
Shear StrengthMPa90
Shore HardnessD Scale
Co-efficient of Frictionμ0.08
Water Absorption @ 23 Deg C%0.15
Service Temperature IntermittentᵒC110
Service Temperature ContinuousᵒC100
Melting pointᵒC
Thermal ConductivityW/m.ᵒC
Dielectric StrengthkV/mm
Volume ResistivityΩ.cm
Surface Resistivity
Arc ResistanceSec