Ultra chemical resistant PTFE O-rings—also known as polytetrafluoroethylene or Teflon O-rings—offer the broadest chemical compatibility of any O-ring material, providing an inert, non-reactive seal against virtually all acids, solvents, bases, and aggressive fluids across a temperature range of -100°F to 500°F. At Mutual Screw & Supply, we stock ultra chemical resistant PTFE O-rings in AS568 standard and metric sizes, making them the sealing solution of choice for pharmaceutical, semiconductor, chemical processing, and aerospace applications where no other material will do—browse our selection below or contact our team for assistance.