Torlon® PAI

Get the Best of Both Worlds

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Torlon® PAI (polyamide-imide)combines the exceptional performance of thermoset polyimides with the melt-processing advantage of thermoplastics. Wear-resistance grades offer unsurpassed performance in both dry and lubricated environments. High-strength grades retain their toughness, high strength and high stiffness up to 275°C (525°F), making PAI the industry's highest performing thermoplastic. Its broad chemical resistance includes strong acids and most organics.

PAI exhibits greater compressive strength and higher impact resistance than most advanced engineering plastics. High creep resistance and an extremely low coefficient of linear thermal expansion (CLTE) provide excellent dimensional stability.

Comparison of Torlon® PAI grades

 Torlon-grades comparison

High-Temperature Wear Resistance

Wear-resistant grades Torlon® PAI offers and excellent combination of mechanical and tribological properties. This combines with excellent chemical resistance and high thermal stability to successfully replace metal in high-temperature friction and wear applications, even when lubrication is marginal or non-existent. Specially formulated grades can perform in lubricated environments at exceptionally high pressures and velocities (PV).



Torlon® 4275 grooved test specimen after 100 hours

Wear properties are enhanced by adding carbon fiber and polymeric lubricants such as PTFE. Torlon® PAI offers the best high-temperature wear resistance.

Torsional DMA of wear-resistant Spire® Ultra Polymers


Comparison of friction and wear grades


Specific Strength

High-strength grades of Torlon® PAI exhibit metal-like performance and are routinely specified for precision components used in repetitive-use, load-bearing operations. Glass-fiber and carbon-fiber-filled grades retain their strength and stiffness at high temperature with the added benefit of low creep and excellent fatigue resistance.

Specific tensile strength comparison of Torlon® PAI to metal

BarGraph_Tensile-strength_Torlon-vs-metalNew Component

Mechanical properties comparison of neat plastics [ASTM D790]


Compressive strength comparison of neat plastics [ASTM D695]


Toughness performance comparison


Coefficient of linear thermal expansion comparison

BarGraph_Torlon-CLTE-comparisonNew Component