Glass Fiber/Moly-Filled PTFE

Moly increases the surface hardness of PTFE while decreasing friction. It is commonly added in small amounts and combined with other fillers such as glass.

Glass fiber/Moly-filled PTFE materials are used in seal components when resistance to high pressure and temperature is required along with very good wear resistance.

Glass fiber/Moly-filled PTFE materials prefer a lubricated environment and are used to seal against steel, stainless steel, and chromium-plated surfaces.

PBY Material Codes:

PB10300 - 5% Glass Fiber 5% Moly Grade 4 

PB10303 - 15% Glass Fiber 5% Moly Grade 5 

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Glass Fiber/Moly-Filled PTFE Spec. Summary

Property Test Method Units 5 Glass 5 Moly 15 Glass 5 Moly
Color - - Grey Light Grey
Specific Gravity ASTM D792 - 2.150 - 2.300 2.150 - 2.300
Hardness Shore D ASTM D2240 - 57 - 67 60 - 70
Tensile Strength, min. ASTM D4745 PSI [MPa] 2,000 [13.8] 2,000 [13.8]
Elongation at Break, min. ASTM D4745 % 200 150
Second Melt Peak Temp. ASTM D3418 °F [°C] 621 [327] 621 [327]
Glass Transition Temp. ASTM D3418 °F [°C] -143 [-97]; 246 [119] -143 [-97]; 246 [119]

Material Available In:

Glass Fiber/Moly-Filled

Glass Fiber/Moly-Filled Tubes

Glass Fiber/Moly-Filled Sheets

Glass Fiber/Moly-Filled PTFE Material Properties

  • Increased Hardness

  • Reduced starting friction coefficient and steady-state wear

  • Negligible electrical properties effects

  • Inert

Typical Applications for Glass Fiber/Moly-Filled PTFE

  • High-temperature applications such as aircraft engines

  • Valve Seats, Seals and HPLC Applications

Glass Fiber/Moly-Filled PTFE Requirements

PB10300T meets ASTM D4745 Type I Grade 4 requirements.

PB10303G meets ASTM D4745 Type I Grade 5 requirements and AMS3678/3 requirements.


Glass Fiber/Moly-Filled PTFE Material Data Sheet Downloads

PB10300T - Material Data Sheet

PB10303G - Material Data Sheet

Glass Fiber/Moly-Filled PTFE Spec. Compliance



  • Wypych, George. Handbook of Polymers. 2nd Ed., ChemTec/Publishing, 2016.
  • Ebnesjjad, Sina. Fluoroplastics Vol1 & Vol2. 2nd Ed., Elsevier Inc., 2015.
  • Aerospace Materials Specifications for PTFE materials (AMS3678)
  • American Society for Testing and Materials (ASTM) Standards