Grade XX Paper Phenolic is a thermoplastic polymer reinforced with paper fibers. It is a light-weight material which can be used in a variety of applications as a more-durable glass substitute.  Paper-based phenolic is the most economical of the laminates, yet provides significant electrical properties and good mechanical properties.  The more X’s the better the electrical properties, while the fewer X’s represent superior mechanical properties.  Paper grades can be modified by adding plasticizers to make them more conducive to punching resulting in a “P” suffix added to the “X” designation (XP, XXP, XXXP).

  • Grade XX certifies to MIL-I-24768/11 (PBG),
  • MIL-I-24768/21 (PBG-P)
MechanicalASTM Test MethodValueUnits
Strength to Weight Ratio--ksi
Specific Gravity @73 FD7921.34-
Tensile Strength @73 F, (ult)/(yld)D63816,000psi
Tensile Modulus of Elasticity @73 FD638-psi
Tensile Elongation at Break @73 FD638-%
Flexural Strength @73 FD79015,000psi
Flexural Modulus of Elasticity @73 FD7901,400,000psi
Shear Strength @73 FD73211,000psi
Comprehensive Strength, (% Deformation) @73 FD69534,000 (10)psi
Comprehensive Modulus of Elasticity @73 FD695-psi
Hardness, Rockwell, Scale as noted @73 FD785M105-
Hardness, Durometer, Shore D @73 FD2240--
Izod Impact, (Notched) @73 FD256 Type A1.3ft-lb/in of notch
Coefficient of Friction, (Dry vs Steel) Dynamic---
Limiting PV, (with 4 to 1 factor of safety applied)--psi-ft/min
ThermalASTM Test MethodValueUnits
Coefficient of Linear Thermal Expansion @73 FE-831 (TMA)-in/in/F
Heat Deflection Temperature @264 psiD648-F
Tg-Glass transition termperature, (Amorphous)D3418-F
Melting Point, (VS=Vicat Softening Temp.)D3418-F
Continuous Service Temperature in Air, (Max.)-285F
Thermal Conductivity--BTU-in/hr-ft2-F
ElectricASTM Test MethodValueUnits
Dielectric Strength, Short TermD149500Volts/mil
Volume ResistivityD257-ohm-cm
Dielectric Constant @10E6 HzD1505.5-
Dissipation Factor @10E6 HzD1500.045-
Flammability @3.1 mm unless notedUL94HB-
H2OASTM Test MethodValueUnits
Water Absorption, Immersion, 24 hoursD570(7)0.55% by weight
Water Absorption, SaturationD570(7)-% by weight