The optimal balance of chemical, mechanical and thermal propertieshex head

PEEK hex head bolts (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 hex head bolts 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 bolts 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 hex head bolts can be reinforced with glass or carbon fibers for improved strength and stiffness properties. Reinforced PEEK hex head bolts offer greater mechanical robustness especially in applications beyond 350°F (175°C).


  • Viewed by the medical community as an advanced biomaterial, PEEK hex head bolts are used in medical implants and are compatible with a high-resolution magnetic resonance imaging (MRI).
  • PEEK bolts 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 hex head bolts are used in many electronics from cell phones to circuit boards for their lightweight strength and reduced noise, vibration and harshness (NVH).

Bolts made from customer specified PEEK grades are available upon request. See our online store (right side) for common PEEK bolts or contact us for specialty or quantity requests.

Bolt Types Available: Hex Bolts

PEEK Hex Head Bolt Features and Benefits

It is important to differentiate between a PEEK hex head bolt and hex head cap screw. Often people assume they are the same, but they are actually very different fasteners in terms of how they are manufactured, as well as from an application perspective. Regardless of your choice, PEEK hex heads offer strong, stable joints because of their large head service. 

The Hex Comparison

Hex Head Bolts

Hex Head Cap Screw
  • Hex bolts have a flat end and lack the washer face under the head.
  • Appropriate for when mechanical properties are more important than dimensional tolerances.
  • Features flat washer facing under the bolt head.
  • Also called a finished hex bolt. 
  • Has tighter tolerances on the body dimensions. 
  • Best used for precise applications where tight tolerances on the body dimensions are required. 


Common PEEK Bolt 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

·        Hex boltshave a flat end and lack the washer face under thehead.

·        Appropriate for when mechanical properties are more important than dimensional tolerances.

  Online Ordering


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