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Torlon® / PAI (Polyamide-imide)

PAI (polyamide-imide) is a melt-processable plastic that has exceptional physical and chemical properties. It performs well under severe stress conditions at continuous temperatures as high as 500° F. Torlon® is an amorphous material with a Tg (glass transition temperature) of 537° F. Outstanding resistance to wear, creep and chemicals—including strong acids and most organics—make Torlon® ideal for severe service environments. Torlon® also has superior electrical and structural characteristics at high temperatures, excellent radiation resistance, an extremely low coefficient of linear thermal expansion, and exceptional dimensional stability. Typical applications include non-lubricating bearings, seals, valves, compressor and piston parts, bearing cages, bushings, and thrust washers.

Key Properties
  • Maintains strength and stiffness to 500° F
  • Minimal expansion rate to 500° F
  • Excellent wear resistance in bearing grades
  • Withstands harsh thermal, chemical and stress conditions
Standard Shapes and Forms

Sheet: .187” – 1” thick

Rod: .093” – 5” diameter

Tubular Bar: 1.25” - 4” OD / .75” – 2.25” ID

The range of sizes and shapes are grade specific, please contact us for more information.

Extruded or Injection-Molded Grades

Torlon® 4203

Torlon® 4203 has excellent compressive strength and the highest elongation of the Torlon® grades. It provides electrical insulation and exceptional impact strength. This grade typically is used for electrical connectors and insulators because of its high dielectric strength. Torlon® 4203 also is an exceptional choice for wear applications involving impact loading and abrasive wear.

Torlon® 4301

Torlon® 4301 has the same basic physical and chemical properties as Torlon® 4203 but is designed for use mainly for wear and friction parts. It offers a very low expansion rate, low coefficient of friction and causes little or no slip-stick in bearing applications. It has a flexural modulus of 1 million psi, a value higher than for most advanced engineering plastics. This grade does exceptionally well in service-wear applications such as non-lubricated bearings, seals, bearing cages and reciprocating compressor parts.

Extruded Grades

Torlon® 4XG

Torlon® 4XG is a 30 percent glass-reinforced grade. Glass is added for improved load capacity. Torlon® 4XG offers high rigidity and retention of stiffness. This grade is ideally suited for applications in the electrical/electronic, business equipment, aircraft and aerospace industries.

Torlon® 4XCF

Torlon® 4XCF is a 30 percent carbon-fiber reinforced grade. Carbon fibers are added for nonabrasive wear performance. Torlon® 4XCF provides exceptional stiffness and nonabrasive wear performance and has the lowest coefficient of thermal expansion of the four Torlon® grades.

Technical Notes

As Torlon® PAI has a relatively high moisture absorption rate, parts used in high temperature service or made to tight tolerances should be kept dry prior to installation. Thermal shock resulting in deformation can occur if moisture laden parts are rapidly exposed to temperatures above 400°F (205°C).