PEEK

Specify the grade and manufactured form

Victrex 450G PEEK lists 152°C HDT at 1.8 MPa, unannealed, by ISO 75-2/Af. Its 343°C melting temperature is a separate ISO 11357-3 result. Use the actual load, exposure duration and permissible deformation when assessing a heated component. Victrex 450G thermal tests

PEEK is polyetheretherketone, a semi-crystalline thermoplastic. Victrex identifies 450G as an unreinforced, natural-color granule grade for injection molding and extrusion. Its catalog separately identifies glass-fiber, carbon-fiber and other formulations. Those products are not interchangeable property sets. Victrex grade catalog, 450G product sheet

Keep resin identity separate from stock-shape identity. Ensinger notes that TECAPEEK products may use Victrex PEEK or Syensqo KetaSpire polymer. If the application requires a particular resin source, make that requirement explicit and confirm traceability rather than assuming the stock-shape trade name guarantees it. Ensinger stock-shape declaration

Named resin data and test context

Victrex's 450G sheet gives these nominal entries:

These are grade-specific comparison data, not finished-part allowables. Victrex 450G, revision March 2026

Victrex states that processing conditions are typical laboratory conditions and that properties and shrinkage depend on geometry, molding and flow direction. Use the complete current grade procedure when developing a process; one temperature or shrinkage entry cannot define production. Victrex processing qualifications, p. 3

Stock-shape example and dimensional assessment

Ensinger's TECAPEEK natural sheet lists 116 MPa tensile strength at 50 mm/min and 4200 MPa tensile modulus at 1 mm/min, by DIN EN ISO 527-2 with type-1b specimens. It generally uses extruded, machined specimens at reference dimensions and labels the data as comparison guidelines rather than guaranteed specification values. Ensinger specimen and data qualifications

Ensinger lists longitudinal CLTE 5 × 10⁻⁵/K over 23–60°C. As original preliminary arithmetic, a 100 mm free length heated uniformly across that interval expands by 100 × 5 × 10⁻⁵ × 37 = 0.185 mm. This excludes restraint, gradients, moisture changes and property variation; it is not a fit prediction for a polymer part constrained by metal. Ensinger thermal-expansion interval

For precise components, define measurement temperature, conditioning and stabilization after machining. Qualify workholding, material-removal sequence, heat input and any supplier-recommended intermediate treatment. Recheck critical dimensions in the acceptance state rather than immediately after a demanding cut.

Long-term temperature and wear are separate qualifications

MCG's Ketron TX PEEK is an internally lubricated stock-shape material. Its 250°C continuous allowable service temperature in air is tied to a thermal-aging basis: after at least 20,000 hours, tensile strength measured at 23°C has fallen by about 50%. Its note also says allowable temperature depends on mechanical stress and duration. This is not a promise that a loaded part retains its initial performance at 250°C. Ketron TX temperature definition, note 3

For sustained loads, obtain applicable creep or relaxation data and define allowable deformation or retained force. Keep short-term strength, thermal aging and cyclic fatigue separate. Qualification should represent the actual grade, processing and exposure rather than a generic “high-temperature plastic” rating.

The same TX sheet gives dynamic friction 0.25–0.35 under a pin-on-disk-like test: 3 MPa, 0.33 m/s, steel Ra 0.7–0.9 µm, 23°C and 50% RH. It is not a universal friction coefficient for all PEEK bearings. Ketron TX wear-test conditions, note 18

For sliding service, define the counterface, finish, lubrication, contamination, geometry, pressure, velocity and heat removal. Test the relevant pair and duty cycle. A lubricated formulation's result should not become an unfilled material's dry-running limit.

Environment, joining and approval boundaries

Specify chemical exposure by formulation, concentration, temperature, contact time and applied stress. Obtain grade-specific compatibility evidence and test representative components where required. A broad chemical-resistance description cannot establish every solvent, oxidant or cleaning-cycle application. Low absorption likewise does not mean zero dimensional response.

Define joining and assembly processes separately, including preparation, inserts, fastener loads, bonding or welding procedures, and inspection. Assess stress concentration, thermal expansion mismatch and retained function over time. Bulk tensile strength cannot establish a joint's capacity or a seal's leakage performance.

For medical, food-contact, electrical or flame requirements, require documentation for the exact grade, color, thickness and intended use. A resin classification is not automatic approval of a machined stock shape or completed device. Preserve the supplier's test and listing limits rather than describing all PEEK as universally compliant.

Release record and source dates

Retain grade, supplier/lot, supplied form, manufacturing and drawing revisions, conditioning and required inspection/functional results. Review substitutions against the entire service and manufacturing requirement.

Sources reviewed November 1, 2026. Victrex's 450G PDF prints Revision Date: March 2026. Ensinger's cited regional sheet prints 2023/07/19, Version AG. Ketron TX prints Date of issue / revision: 07/03/2023 and ©2023; the numerical date is preserved without assuming its day/month ordering.

Related reference

Material selection through production