Pure expanded mineral graphite flake or chip particles are subjected to laminar swelling and are subsequently calendered into flexible foil without the use of any separate binder, a feature which guarantees a high degree of purity not associated with other graphite derivatives. The foil is processed in a number of ways to adapt the unique properties of the material to a variety of sealing needs The raw material is a mineral that is mined in a similar way to coal.


The sealability of graphite is akin to that associated with elastomeric materials but its temperature capability far exceeds that of even the most exotic rubber compound. Add to this an outstanding resistance to a wide range of organic and inorganic chemicals and it is easy to see why many regard graphite as one of the most important additions to the gasket manufacturer’s stock holding since the advent of polytetrafluoroethylene (PTFE).

Purity / Sulphur Content max. ASTM C-816 98% / 700 ppm
Bulk Density ASTM C-559 1.0 to 1.1 g/cc
Ash Content ASTM C-561 Less than 0.5%
Leachable Chloride / Fluorides 50 ppm max. ASTM D-512
Temperature Range -200°C to +3000°C (Non-Oxidising)
-200°C to + 500°C (Oxidising)
-200°C to + 650°C (Steam)
Tensile Strength / Stress Relaxation 998 psi / DIN 52913 - 48 N/mm²
Shore Hardness (D) / Creep Relaxation 30 / At 100°C ASTM F-38 < 5%
Sealability, ml/h Fuel A ASTM F-37B <0.2 to 0.5
Electrical Resistance 900 x 10-6 ohm cm parallel on surface
250,000 x 10-6 ohm perpendicular to surface
Thermal Conductivity 120 Kcal/m. Hr.°C parallel to surface
4 Kcal/m Hr.°C perpendicular to surface
Coefficient of Thermal Expansion 5 x 10-6 / °C parallel to surface
2 x 10-6 / °C perpendicular to surface
Compressive Strength more than 800 kg/cm²
Ignition Loss / Operating Pressure less than 1% / 140 bar (2058 psi)
Resilient Rate / Density more than 30% / 0.7 to 1.1 gr cm³
Compressibility ASTM F36A-66 40 to 45%

Pure graphite is available in sheets or rolls and in a wide range of thicknesses


Contact details

Call us

Kent Gaskets Ltd

Unit 61, The Oaks

Manston Business Park



CT12 5FS


Tel : 01843 854800


Sales : 


annemarie@kentgaskets.co.uk steve@kentgaskets.co.uk

Accounts : andrew@kentgaskets.co.uk



Yorkshire Gaskets Ltd

Unit 7A

Lawefield Park, Lawefield Lane



Tel: 01924 200100






For emergencies please call 01924 200100 and you will be transferred to a member of staff who is on call.


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