The optimal balance of chemical, mechanical and thermal propertiesFlat Head All Three

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


  • Viewed by the medical community as an advanced biomaterial, PEEK flat head 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 flat head screws are used in many electronics from cell phones to circuit boards for their lightweight strength and reduced noise, vibration and harshness (NVH).

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

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

PEEK Flat Head Screw Features and Benefits

PEEK flat head screws are characterized by having a head with a top flat surface (which can feature either a slotted, phillips or allen driver) and bottom that is cone shaped or countersunk. With this design, the head of the screw can align flush or below the surrounding surface having obvious benefits.

PEEK Slotted vs. Phillips Driver 

 Slotted Head Advantages Phillips Head Advantages 
  • Slotted head screws tend to strip less than Philips, especially in harsh environments
  • Slotted heads are typically better in applications where it's going to be unscrewed and re-done periodically, as the head tends to wear less.

  • In dirty environments, a flat head is much easier to clean out

  • Phillips head offers a much stronger joint since it can tolerate more torque.




Countersink Angle

For most flat head screw designs the angle of countersink is usually 82° for UNC and UNF applications however other angles ranging from 60° -120° could be specified. 

Thread Type Normal Flat Head Countersink Angle



Aerospace 100°
ISO Metric / Imperial 90°


Common PEEK 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® Screws

PEEK Chemical Resistance

PEEK Properties

PEEK Properties

  Online Ordering


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