The optimal balance of chemical, mechanical and thermal propertieshex head

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

Applications

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

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

Screw TypesFlat Head ScrewsHex Cap ScrewsPan Head ScrewsSet ScrewsSocket Head Cap Screws


PEEK Hex Head Cap Screw Features and Benefits

It is important to differentiate between a PEEK hex head cap screw and hex head bolt. 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 Cap Screw Hex Head Bolts
  • Precise applications where tight tolerances on the body dimensions are required. 
  • Features flat washer facing under the bolt head.
  • Also called a finished hex bolt.
  • Appropriate for when mechanical properties are more important than dimensional tolerances. 
  • Hex bolts have a flat end and lack the washer face under the head.

PEEK Hex Head Cap Screw Advantages  

The most important feature of a PEEK hex head cap screws is that it has a larger bearing surface area which provide better clamping pressure than other type of fastener such as a socket head cap screw. Additionally, since debris build up is less of an issue with this style of fastener verses a socket head cap screw, they are ideal of dirty applications where particles could clog up a socket. Though PEEK socket heads are typically used for tight access applications, hex heads can be a better choice when there is only side clearance available for tightening. 


Common PEEK Hex Head Cap Screw 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® Hex Head Cap Screws

PEEK Chemical Resistance


PEEK Properties

PEEK Properties

 

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