Material Comparisons Material Comparison

PEEK vs PEKK: Which High-Performance Plastic Wins?

Tensile data verified against MatWeb.com database & manufacturer datasheets · Last updated July 2026

Published: 2026-06-02

Quick Reference

Which Material Should You Choose?Choose PEEK if:injection molding (better processabilityChoose PEKK if:High mechanical strength requiredPrice ComparisonPEEK: $80-200/kg vs PEKK: $100-250/kg · Prices vary by grade and quantityPEEK and PEKK share...

°C PEEK 343°C PTFE 260°C Ultem PEI 217°C PPS 180°C
Continuous service temperature comparison — high-performance thermoplastics. Data from manufacturer specifications.

Which Material Should You Choose?

Choose PEEK if:

  • injection molding (better processability

Choose PEKK if:

  • High mechanical strength required

Price Comparison

PEEK: $80-200/kg vs PEKK: $100-250/kg · Prices vary by grade and quantity

PEEK and PEKK share PAEK chemistry — PEKK has higher ketone/ether ratio → higher Tg (162 vs 143°C), higher melt point. PEKK preferred for aerospace composites (better CAI). PEEK preferred for injection molding (better processability, lower cost). PEKK costs ~50-80% more.

Comparison at a Glance

Tensile StrengthPEEK: 100 vs PEKK: 110 MPa
Melting PointPEEK: 343 vs PEKK: 360°C
Shrinkage RatePEEK: 1.2 vs PEKK: 0.8%
Flexural ModulusPEEK: 4.1 vs PEKK: 4.5 GPa
HdtPEEK: 160 vs PEKK: 175°C

Equivalents & Cross-References

Equivalent / AlternateAction
Victrex PEEK vs Kepstan PEKK
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Frequently Asked Questions

Which costs more?

PEKK ~50-80% more expensive due to complex monomer synthesis. PEEK is first choice for injection molding. PEKK specified when extra 20°C Tg is required.

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References & Industry Standards

  • ASTM International. Standard Specifications for Engineering Plastics & Thermoplastics. astm.org
  • UL Prospector. Plastics & Elastomers Material Database. ulprospector.com
  • MatWeb. Material Property Data for Engineering Thermoplastics. matweb.com
  • ISO 1043. Plastics — Symbols and Abbreviated Terms. iso.org