Polyether ether ketone (PEEK) is a colorless organic thermoplastic polymer in the polyaryletherketone (PAEK) family, used in engineering applications.


PEEK is a semi-crystalline thermoplastic with excellent mechanical and chemical resistance properties that are retained to high temperatures. The processing conditions used to mold PEEK can influence the crystallinity, and hence the mechanical properties. The Young's modulus is 3.6 GPa and its tensile strength 90 to 100 MPa. PEEK has a glass transition temperature of around 143 °C (289 °F) and melts around 343 °C (662 °F). Some grades have a useful operating temperature of up to 250 °C (482 °F) . The thermal conductivity increases nearly linearly versus temperature between room temperature and solidus temperature.  It is highly resistant to thermal degradation as well as attack by both organic and aqueous environments. It is attacked by halogens and strong Bronsted and Lewis acids as well as some halogenated compounds and aliphatic hydrocarbons at high temperatures.


Because of its robustness, PEEK is used to fabricate items used in demanding applications, including bearings, piston parts, pumps, HPLC columns, compressor plate valves, and cable insulation. It is one of the few plastics compatible with ultra-high vacuum applications. PEEK is considered an advanced biomaterial used in medical implants. It is finding increased use in spinal fusion devices and reinforcing rods. It is extensively used in the aerospace, automotive, and chemical process industries. PEEK's mechanical properties at elevated temperatures have led to it being used in at least two varieties of Reprap extruder as thermal insulation. This means the main mechanical structure of the extruder can be made of the same material that is being extruded, provided that the PEEK insulator prevents heat from traveling beyond the intended melt zone.

Processing Options

PEEK melts at a relatively high temperature (343 °C / 649.4 °F) compared to most other thermoplastics. In the range of its melting temperature it can be processed using injection molding or extrusion methods. In its solid state PEEK is readily Machinable, for example, by (CNC) milling machines and is commonly used to produce high-quality plastic parts that are thermostable and both electrically and thermally insulating. PEEK is often considered a high-end engineering plastic, such as Delrin, PTFE or nylon.

Material Grades

PEEK-Unfilled (Virgin Grade)

PEEK-30% Glass Reinforced

PEEK-30% Carbon Reinforced

PEEK HPV (Bearing Grade)

PEEK LSG (Medical Grade)