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PEEK-Bearing-Grade vs PEEK-Medical-Grade

Polymer · grade comparison

PEEK-Bearing-Grade and PEEK-Medical-Grade are both polymer grades. PEEK-Bearing-Grade is the stronger of the two: yield strength 115 MPa (16.7 ksi) against 98 MPa (14.2 ksi) for PEEK-Medical-Grade, about 17% more; tensile strength follows at 130 MPa (18.9 ksi) vs 100 MPa (14.5 ksi). In exchange, PEEK-Medical-Grade is the more ductile: elongation 30% versus 2.5% for PEEK-Bearing-Grade. PEEK-Medical-Grade is lighter (1.3 g/cm³ vs 1.44 g/cm³ for PEEK-Bearing-Grade) and PEEK-Bearing-Grade is stiffer (7.7 GPa vs 3.8 GPa). On the shop floor, PEEK-Medical-Grade machines more easily (very good vs good) and PEEK-Medical-Grade welds better (good vs poor).

PEEK-Bearing-GradeChoose it when strength drives the design.

PEEK-Medical-GradeChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.

PEEK-Bearing-Grade vs PEEK-Medical-Grade: properties

PEEK-Bearing-GradePEEK-Medical-Grade

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

7.7 GPa1.1 Msi
3.8 GPa0.55 Msi

Shear Modulus

2.8 GPa0.41 Msi
1.4 GPa0.2 Msi

Poisson's Ratio

0.38
0.4

Tensile Strength (Ultimate)

130 MPa18.9 ksi
100 MPa14.5 ksi

Yield Strength (0.2% offset)

115 MPa16.7 ksi
98 MPa14.2 ksi

Elongation at Break

2.5%
30%

Compressive Strength

140 MPa20.3 ksi
125 MPa18.1 ksi

Compressive Modulus

6 GPa0.87 Msi
3.6 GPa0.52 Msi

Flexural Strength

180 MPa26.1 ksi
165 MPa23.9 ksi

Flexural Modulus

7.2 GPa1 Msi
4.1 GPa0.59 Msi

Shear Strength

68 MPa9.9 ksi
60 MPa8.7 ksi

Fracture Toughness (K_IC)

3.5 MPa·√m3.2 ksi·√in
4 MPa·√m3.6 ksi·√in

Izod Impact, Notched

45 J/m0.84 ft·lbf/in
70 J/m1.3 ft·lbf/in

Hardness, Shore D

87 Shore D
85 Shore D

Hardness, Rockwell M

100 HRM
99 HRM

Bulk Modulus

—
4 GPa0.62 Msi

Hardness, Rockwell R

—
126 HRR

Physical

Density and transition temperatures.

Density

1.44 g/cm³0.05 lb/in³
1.3 g/cm³0.05 lb/in³

Glass Transition (Tg)

150°C302 °F
143°C289 °F

Water Absorption (24 h)

0.12%
0.14%

Water Absorption (Saturation)

0.4%
0.45%

Same in both: Melting Temperature (Tm) 343°C649 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

0.9 W/m·K0.52 BTU/hr·ft·°F
0.25 W/m·K0.14 BTU/hr·ft·°F

Specific Heat Capacity

1,250 J/kg·K0.3 BTU/lb·°F
1,340 J/kg·K0.32 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

25 µm/m·K13.9 µin/in·°F
47 µm/m·K26.1 µin/in·°F

Heat Deflection Temp. @ 0.45 MPa

325°C617 °F
315°C599 °F

Heat Deflection Temp. @ 1.8 MPa

300°C572 °F
152°C306 °F

Vicat Softening Point (B50)

320°C608 °F
315°C599 °F

Max Service Temperature (short-term)

310°C590 °F
300°C572 °F

Same in both: Max Service Temperature (continuous) 250°C482 °F · Min Service Temperature -60°C-76 °F · Limiting Oxygen Index 35%

Electrical

Conductivity and insulation.

Electrical Resistivity

1,000 Ω·m3.94×10¹⁰ µΩ·in
1×10¹⁴ Ω·m3.94×10²¹ µΩ·in

Volume Resistivity

100,000 Ω·cm
1×10¹⁶ Ω·cm

Surface Resistivity

100,000 Ω
1×10¹⁵ Ω

Dielectric Strength

—
22 kV/mm559 V/mil

Dielectric Constant (1 MHz)

—
3.2

Dissipation Factor (1 MHz)

—
0.003

Comparative Tracking Index (CTI)

—
150 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

UV / Weathering Resistance

70 / 100
35 / 100

Same in both: Corrosion Resistance 95 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

55 / 100
70 / 100

Weldability

20 / 100
60 / 100

Formability (cold)

10 / 100
40 / 100

Polishability

55 / 100
80 / 100

Mold Shrinkage

0.3%
1.2%

Melt Flow Rate

6 g/10 min
3.5 g/10 min

Same in both: Processing Melt Temperature (typ.) 380°C716 °F · Mold Temperature (typ.) 190°C374 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

300 MJ/kg128,977 BTU/lb
290 MJ/kg124,678 BTU/lb

Embodied Water

450 L/kg53.9 gal/lb
600 L/kg71.9 gal/lb

Same in both: Embodied Carbon (primary production) 13 kg CO₂/kg · Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

90 kN·m/kg
77 kN·m/kg

Specific Stiffness (E / density)

5.3 MN·m/kg
2.9 MN·m/kg

Modulus of Resilience

859 kJ/m³
1,264 kJ/m³

Thermal Diffusivity

0.5 mm²/s
0.1 mm²/s

Thermal Shock Resistance Index

1
0

Strength versus weight

Yield strength against density for every polymer grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

0.1110100123Density (g/cm³)Yield strength (MPa) — log scalePEEK-Bearing-GradePEEK-Medical-Grade

Manufacturing and finishing

CapabilityPEEK-Bearing-GradePEEK-Medical-Grade
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

PEEK-Bearing-Grade vs PEEK-Medical-Grade — frequently asked

Is PEEK-Bearing-Grade stronger than PEEK-Medical-Grade?

Yes. PEEK-Bearing-Grade has a typical yield strength of 115 MPa (16.7 ksi) against 98 MPa (14.2 ksi) for PEEK-Medical-Grade — about 17% more. Tensile strength is 130 MPa (18.9 ksi) vs 100 MPa (14.5 ksi).

Which is cheaper, PEEK-Bearing-Grade or PEEK-Medical-Grade?

Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, PEEK-Bearing-Grade or PEEK-Medical-Grade?

PEEK-Medical-Grade. Its machinability rates very good (70/100) against good (55/100) for PEEK-Bearing-Grade; for welding the order is PEEK-Medical-Grade first (good, 60/100) then PEEK-Bearing-Grade (poor, 20/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in PEEK-Bearing-Grade and PEEK-Medical-Grade side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.