ForMatter/Materials/polymer/PEEK (Unfilled)
mat_peek_unfilled

PEEK (Unfilled)

semi-crystalline aromatic thermoplastic, high-performance · PEEK, polyetheretherketone, Victrex PEEK, Kepstan, Solvay KetaSpire
highlast updated 2026-04-27

The polymer engineering ranks among metals — the one that holds its strength to 250 °C, survives radiation that would degrade nearly any other polymer, and is biocompatible enough for spinal-implant cages. The cost is the price (often $100/kg as virgin pellet) and the molding temperature (380 °C — most injection-molders can't process it). The aerospace, oil-and-gas, and medical-implant default when the alternative is metal.

Semi-crystalline aromatic polyaryletherketone. Tm 343 °C, Tg 143 °C. Density 1.32 g/cm³. Tensile 100 MPa, elastic modulus 3.6 GPa. Continuous service temperature 250 °C. Compatible with steam autoclave sterilization, gamma-radiation sterilization, and EtO sterilization — the medical-implant trifecta. Crystallinity-dependent properties; molding-cycle parameters affect part performance more than for most thermoplastics.

Mechanical

  • tensile strength · MPa100
  • yield strength · MPa95
  • elastic modulus · GPa3.6
  • elongation (at break) · %30
  • density · kg/m³1320
source: MakeItFrom; Victrex PEEK 450G datasheet

Thermal

  • melting point · °C343
  • glass transition · °C143
  • service max · °C250
  • thermal conductivity · W/m·K0.25
source: Victrex datasheet

Sustainability

  • embodied carbon · kg CO₂e/kg110
  • recyclabilitymoderate — closed-loop industrial scrap reclaim; not in mainstream curbside
  • biodegradableFalse
  • certificationsASTM F2026 (medical implant grade — Invibio PEEK-OPTIMA), USP Class VI
source: Editorial estimate from ICE / Granta CES EduPack class databases — industry mean, with cradle-to-gate boundary unless otherwise noted. Embodied carbon for any specific product depends on supplier mix, recycled content, and energy grid; verify against a primary source before using these numbers in a sustainability claim.
visual
characteristic warm tan / khaki color (natural grade); pigments to dark colors only — light-color masterbatches degrade at melt temperatures
tactile
rigid, polished surface, denser-feeling than commodity polymers

PBR starter values

finish · matte — open for table, JSON, host snippets, downloads

Principled BSDF defaults derived from the sphere matte finish. Reasonable seed for Blender, Substance, Keyshot, Rhino — tune per material. Or grab the whole library at once: ForMaterials library →

# finish:                   matte
albedo                      #b89e78
metallic                    0.00
roughness                   0.75
ior                         1.45
transmission                0.00
clearcoat                   0.00
sheen                       0.00
anisotropic                 0.00
copy as JSON 
{
  "albedo": "#b89e78",
  "metallic": 0.0,
  "roughness": 0.75,
  "ior": 1.45,
  "transmission": 0.0,
  "clearcoat": 0.0,
  "sheen": 0.0,
  "anisotropic": 0.0
}
Blender 4.x Python 
# Blender 4.x — Principled BSDF
# PEEK (Unfilled) · finish: matte
import bpy
mat = bpy.data.materials.new(name="mat_peek_unfilled")
mat.use_nodes = True
bsdf = mat.node_tree.nodes["Principled BSDF"]
bsdf.inputs["Base Color"].default_value         = (0.4793, 0.3419, 0.1878, 1.0)
bsdf.inputs["Metallic"].default_value           = 0.000
bsdf.inputs["Roughness"].default_value          = 0.750
bsdf.inputs["IOR"].default_value                = 1.450
bsdf.inputs["Transmission Weight"].default_value = 0.000
bsdf.inputs["Coat Weight"].default_value        = 0.000
bsdf.inputs["Sheen Weight"].default_value       = 0.000
bsdf.inputs["Anisotropic"].default_value        = 0.000
KeyShot Python (lux) 
# KeyShot 11+ — lux Python API, Generic material
# PEEK (Unfilled) · finish: matte
# Run from Window → Scripting Console
import lux
mat = lux.createMaterial(name="mat_peek_unfilled", materialType="Generic")
mat.setProperty("diffuse",      (184, 158, 120))   # 8-bit sRGB
mat.setProperty("metallic",     0.000)
mat.setProperty("roughness",    0.750)
mat.setProperty("indexOfRefraction", 1.450)
mat.setProperty("transparency", 0.000)
mat.setProperty("coatingWeight", 0.000)
Substance pbrMetalRough 
{
  "_format": "Substance Designer / Painter \u2014 pbrMetalRough constants",
  "_about": "PEEK (Unfilled) \u00b7 finish: matte",
  "baseColor": {
    "r": 0.4793,
    "g": 0.3419,
    "b": 0.1878
  },
  "metallic": 0.0,
  "roughness": 0.75,
  "ior": 1.45,
  "opacity": 1.0,
  "anisotropyLevel": 0.0,
  "_notes": "Channels listed are the standard Substance pbrMetalRough output. Drop into a Uniform Color node per channel, or as the constant input on a layered stack."
}
glTF 2.0 Metallic-Roughness 
{
  "asset": {
    "version": "2.0",
    "generator": "ForMatter"
  },
  "materials": [
    {
      "name": "mat_peek_unfilled",
      "pbrMetallicRoughness": {
        "baseColorFactor": [
          0.4793,
          0.3419,
          0.1878,
          1.0
        ],
        "metallicFactor": 0.0,
        "roughnessFactor": 0.75
      },
      "extensions": {
        "KHR_materials_ior": {
          "ior": 1.45
        }
      }
    }
  ]
}
USD Preview Surface 
# USD Preview Surface — UsdShade.MaterialLook prim attributes
# PEEK (Unfilled) · finish: matte
def Material "mat_peek_unfilled" {
    token outputs:surface.connect = </mat_peek_unfilled/PreviewSurface.outputs:surface>

    def Shader "PreviewSurface" {
        uniform token info:id = "UsdPreviewSurface"
        color3f inputs:diffuseColor = (0.4793, 0.3419, 0.1878)
        float   inputs:metallic     = 0.000
        float   inputs:roughness    = 0.750
        float   inputs:ior          = 1.450
        float   inputs:opacity      = 1.000
        float   inputs:clearcoat    = 0.000
        token   outputs:surface
    }
}
↓ download glTF material

CNC milling on swarf

surface speed (carbide)300–600 (engineering polymer; harder than commodity plastics)
chipload per tooth3–6 (1/4-inch O-flute endmill)
coolantair blast or flood; PEEK is heat-stable but tools dull faster than on commodity polymers
swarf-compatible toolsend 1/8end 1/4drill 1/8drill 1/4

PEEK is the high-temp engineering polymer — autoclave-safe, biocompatible, expensive. Mills more like a soft metal than a typical plastic. Carbide tools mandatory; HSS dulls in minutes.

Onsrud Cutter plastic feeds & speeds (PEEK table); Victrex PEEK machining guide; Solvay KetaSpire technical bulletin.

→ try this material in swarf
ProcessInjection Molding · CNC Milling · Extrusion · FDM 3D Printing (Fused Deposition Modeling)
Substitutes
Titanium Grade 5 (Ti-6Al-4V)

Second life

repairabilitylow at the part scale — PEEK is a high-temperature thermoplastic that re-melts but rarely repaired; replacement is standard for medical-implant and aerospace PEEK parts.
recyclabilitymoderate — high-value engineering polymer; specialty PEEK recyclers exist (Victrex closed-loop programs); rare in curbside streams.
disposal pathspecialty engineering-polymer recycler.
typical longevity40 years (typical)
failure modes
  • oxidation at sustained high temperature (above 250 °C)
  • fatigue in cyclic load (better than most polymers but worse than metals)
  • cost-prohibitive for most contexts beyond medical / aerospace / oil-and-gas

Victrex PEEK technical literature; Solvay KetaSpire datasheet; Brydson Plastics Materials.

Citations