The optimal balance of chemical, mechanical and thermal propertiesPEEK Blind Flange

PEEK blind flanges (chemically known as Polyetheretherketone) offer a unique combination of properties for some of the most extreme applications. PEEK is classified as semicrystalline thermoplastic and high purity polymer, offering excellent mechanical strength and chemical resistance at high temperatures. PEEK blind flanges offer a high strength alternative to PTFE fluoropolymers.

Key Benefits

  • Excellent resistance to thermal degradation (chemical decomposition caused by heat).
  • Chemically resistance to many oils, alcohols, solvents, and organics as well as harsh acids and bases in low concentrations and temperatures.
  • Hydrolysis resistance provides PEEK ability to retain all physical properties when continuously exposed to water or steam at high temperatures and pressures, as well as offer very low moisture absorption.
  • Outstanding creep resistance allows PEEK flanges to sustain large stresses over long service life.
  • Ability to withstand frequent sterilization processes.
  • V-0 flammability rating with low smoke and toxic gas emission when exposed to flame.
  • Good wear and abrasion resistance.
  • Electrical properties are maintained over a wide frequency and temperature range.
  • Radiation resistance allows PEEK to be used in or be repeatedly sterilized by, high doses of ionizing radiation.

Options for High Strength
Depending on the application, PEEK blind flanges can be reinforced with glass or carbon fibers for improved strength and stiffness properties. Reinforced PEEK blind flanges offer greater mechanical robustness especially in applications beyond 350°F (175°C).


  • Viewed by the medical community as an advanced biomaterial, PEEK blind flanges are used in medical implants and are compatible with a high-resolution magnetic resonance imaging (MRI).
  • PEEK flanges are one of the few plastics compatible with ultra-high vacuum (UHV) which is necessary for many analytic techniques and particle accelerators.
  • Chemical processing and pharmaceutical applications depend on PEEK for it’s chemical resistance, high purity and ability to withstand sterilization processes.
  • PEEK blind flanges are used in many electronics from cell phones to circuit boards for their lightweight strength and reduced noise, vibration and harshness (NVH).

Blind flanges made from customer specified PEEK grades are available upon request.

ResouresFlange DimensionsFlange Bolting Chart

Flange Types Available: Blind FlangesThreaded Flanges

Common PEEK Blind Flange Grades

PEEK 100% / Unfilled

PEEK, with no fillers is unreinforced and 100% polymer. Even without glass or carbon fiber reinforcement, this one of the strongest polymers we offer and well suited for a variety of applications including FDA food contact and other applications requireing high purity. 

PEEK Glass Fiber Reinforced

PEEK 30% Glass Fiber Reinforced provide the same chemical resistance and natural PEEK but nearly doubles in tensile strength.

PEEK Carbon Fiber Reinforced 

PEEK 20% Carbon Fiber Reinforced provides approximately 2.5 times the strength of pure PEEK. 

PEEK Extreme

PEEK Extreme is our proprietary receipe for the highest strength PEEK utilizing carbon fiber reinforcement. This version of PEEK over 3 times stronger than standard unreinforced PEEK. 


Mechanical Properties of PEEK

PEEK Tensile Curves  Tensil Temperature Chart 11 2017

Chemical Resistance of PEEK / Victrex® Bolts

PEEK Chemical Resistance

PEEK Properties

PEEK Properties

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