Form

This specification covers virgin, unfilled polytetrafluoroethylene (PTFE) in the form of extruded rods, tubes, and profiles.

These products have been used typically for parts, such as bushings and insulators, requiring better chemical inertness and dimensional stability up to 500 °F (260 °C) than AMS3657 and better mechanical and electrical properties than AMS3656, but usage is not limited to such applications. For applications such as bearings, seals, and back-up rings that do not require dielectric properties it is recommended to use AMS3678/1 Grade B.

Safety - Hazardous Materials

While the materials, methods, applications, and processes described or referenced in this specification may involve the use of hazardous materials, this specification does not address the hazards which may be involved in such use. It is the sole responsibility of the user to ensure familiarity with the safe and proper use of any hazardous materials and to take necessary precautionary measures to ensure the health and safety of all personnel involved.

Types 1 and 2, which were defined in previous revisions of this specification, have been combined. For documentation which specifies Type 1 or Type 2 of this specification, all of the requirements of this specification now apply.