Sindanyo L21

Sindanyo has been an industry standard in electrical and thermal insulation applications for over 50 years. With a carefully chosen blend of fibres, density modifiers and cement, Sindanyo is still the preferred material in a wide range of applications.

Due to its high arc resistance the L21 grade is used throughout the high voltage switchgear industry and is capable of temperatures up to 250 deg C. Where the H91 on the other hand is has a maximum service temperature of 700 deg C and is used in smelters, foundries and forging plants.


Property Unit of measure Value
Tensile StrengthMpa14
Elongation at Break%
Modulus of ElasticityMPa
Impact Strengthkj/m²5
Compressive StrengthMPa95
Shear StrengthMPa20
Shore HardnessD Scale
Co-efficient of Frictionμ
Water Absorption @ 23 Deg C%16
Service Temperature IntermittentᵒC250
Service Temperature ContinuousᵒC230
Melting pointᵒC
Thermal ConductivityW/m.ᵒC0.5
Dielectric StrengthkV/mm2
Volume ResistivityΩ.cm
Surface Resistivity
Arc ResistanceSec184