Application area: General industry

General facts


Shortening: PAI

Color: Ocher yellow

Common uses: Filled with lubricant, it is used for bearing holders, bearings, bushings, valves, etc. PAI 4301, PAI + Graphite + PTFE (black) is used for rotating parts. PAI 4203 is used for precision parts in high-tech equipment.


The benefits of Torlon 4301

  • Withstands high temperatures (+ 260ºC).
  • Only 4% of the tensile stress is lost after 2000h at + 200ºC.
  • UL index 220ºC.
  • Extremely low friction and abrasion in grades filled with
  • PTFE or graphite.
  • Extremely low thermal expansion.
  • Chemical resistant.
  • Mechanical strength values are stably high throughout the temperature range.
  • Extremely dimensionally stable.
  • Excellent durability.
  • Extremely UV resistant.
  • Extremely resistant to gamma and X-rays.
  • Highest flammability class (UL94-V0).


Limitations of Torlon 4301 PAI

  • Extremely difficult to inject moldings.
  • Attacked by hot alkalis and acids.
  • Some moisture absorption.
  • Not food approved.

Download documents

Material data sheet PAI 4301

Torlon 4301 PAI – specific properties

Torlon 4301 is a general purpose bearing grade polyamide-imide. This PAI plastic contains:

  • 12% graphite
  • 3% PTFE powder for reduced friction
  • a low wear rate.

It is the toughest and most commonly specified of the Torlon wear grades, and is most commonly used for:

  • precision parts in high-tech equipment
  • rotating parts
  • bearing holders
  • bearings
  • bushings
  • valves.