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LCP vs PEEK

Polymer · grade comparison

LCP and PEEK are both polymer grades, both high performance plastic. LCP is the stronger of the two: tensile strength 190 MPa (27.6 ksi) against 100 MPa (14.5 ksi) for PEEK, about 90% more. In exchange, PEEK is the more ductile: elongation 30% versus 2% for LCP. PEEK is lighter (1.3 g/cm³ vs 1.61 g/cm³ for LCP) and LCP is stiffer (15 GPa vs 3.7 GPa). On the shop floor, PEEK machines more easily (very good vs fair) and PEEK welds better (fair vs poor).

LCPChoose it when strength drives the design.

PEEKChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.

LCP vs PEEK: properties

LCPPEEK

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

15 GPa2.2 Msi
3.7 GPa0.54 Msi

Poisson's Ratio

0.35
0.4

Tensile Strength (Ultimate)

190 MPa27.6 ksi
100 MPa14.5 ksi

Elongation at Break

2%
30%

Flexural Strength

235 MPa34.1 ksi
165 MPa23.9 ksi

Flexural Modulus

14 GPa2 Msi
4 GPa0.58 Msi

Shear Strength

70 MPa10.2 ksi
55 MPa8 ksi

Izod Impact, Notched

100 J/m1.9 ft·lbf/in
75 J/m1.4 ft·lbf/in

Hardness, Shore D

88 Shore D
86 Shore D

Hardness, Rockwell M

85 HRM
99 HRM

Shear Modulus

—
1.3 GPa0.19 Msi

Bulk Modulus

—
6 GPa0.87 Msi

Yield Strength (0.2% offset)

—
100 MPa14.5 ksi

Compressive Modulus

—
3.6 GPa0.52 Msi

Fracture Toughness (K_IC)

—
3.5 MPa·√m3.2 ksi·√in

Hardness, Rockwell R

—
126 HRR

Same in both: Compressive Strength 130 MPa18.9 ksi

Physical

Density and transition temperatures.

Density

1.61 g/cm³0.06 lb/in³
1.3 g/cm³0.05 lb/in³

Melting Temperature (Tm)

280°C536 °F
343°C649 °F

Glass Transition (Tg)

110°C230 °F
143°C289 °F

Water Absorption (24 h)

0.03%
0.12%

Water Absorption (Saturation)

0.08%
0.45%

Thermal

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

Thermal Conductivity

0.4 W/m·K0.23 BTU/hr·ft·°F
0.25 W/m·K0.14 BTU/hr·ft·°F

Specific Heat Capacity

1,100 J/kg·K0.26 BTU/lb·°F
1,340 J/kg·K0.32 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

12 µm/m·K6.7 µin/in·°F
47 µm/m·K26.1 µin/in·°F

Max Service Temperature (continuous)

220°C428 °F
250°C482 °F

Min Service Temperature

-50°C-58 °F
-60°C-76 °F

Heat Deflection Temp. @ 0.45 MPa

255°C491 °F
315°C599 °F

Heat Deflection Temp. @ 1.8 MPa

230°C446 °F
152°C306 °F

Limiting Oxygen Index

40%
35%

Max Service Temperature (short-term)

280°C536 °F
300°C572 °F

Vicat Softening Point (B50)

—
315°C599 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹³ Ω·m3.94×10²⁰ µΩ·in
1×10¹⁴ Ω·m3.94×10²¹ µΩ·in

Dielectric Strength

35 kV/mm889 V/mil
21 kV/mm533 V/mil

Dielectric Constant (1 MHz)

4
3.2

Dissipation Factor (1 MHz)

0.008
0.003

Volume Resistivity

1×10¹⁵ Ω·cm
1×10¹⁶ Ω·cm

Surface Resistivity

1×10¹⁴ Ω
1×10¹⁵ Ω

Comparative Tracking Index (CTI)

200 V
150 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

92 / 100
90 / 100

UV / Weathering Resistance

60 / 100
45 / 100

Manufacturability

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

Machinability

50 / 100
70 / 100

Weldability

25 / 100
45 / 100

Formability (cold)

10 / 100
30 / 100

Polishability

30 / 100
70 / 100

Mold Shrinkage

0.1%
1.2%

Processing Melt Temperature (typ.)

330°C626 °F
380°C716 °F

Mold Temperature (typ.)

90°C194 °F
180°C356 °F

Melt Flow Rate

—
3 g/10 min

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

200 MJ/kg85,985 BTU/lb
290 MJ/kg124,678 BTU/lb

Embodied Carbon (primary production)

9 kg CO₂/kg
15 kg CO₂/kg

Embodied Water

—
450 L/kg53.9 gal/lb

Same in both: Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

118 kN·m/kg
77 kN·m/kg

Specific Stiffness (E / density)

9.3 MN·m/kg
2.8 MN·m/kg

Thermal Diffusivity

0.2 mm²/s
0.1 mm²/s

Same in both: Thermal Shock Resistance Index 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 scalePEEKLCP

Manufacturing and finishing

CapabilityLCPPEEK
CNC machining—Yes
Sheet metal—Yes
3D printing—Yes
Default conditionGF30Virgin
Relative cost$$$$$ Specialty$$$$$ Specialty
Min. machined wall—0.8 mm
Best machined surface—Ra 0.8 µm
Conductive Coating—Yes
Dyeing (Nylon)—Yes
Painting—Yes
Primer Coating—Yes
Tinted Coating—Yes
Vacuum Metallization—Yes
Waterproof Coating—Yes

Both are offered for Injection molding. They share 5 finishes: Chrome Plating (Plastic), EMI Shielding Coating, Soft Touch Coating, Spray Painting, UV Coating.

LCP vs PEEK — frequently asked

Is LCP stronger than PEEK?

Yes. LCP has a typical tensile strength of 190 MPa (27.6 ksi) against 100 MPa (14.5 ksi) for PEEK — about 90% more.

Which is cheaper, LCP or PEEK?

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

Which is easier to machine, LCP or PEEK?

PEEK. Its machinability rates very good (70/100) against fair (50/100) for LCP; for welding the order is PEEK first (fair, 45/100) then LCP (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in LCP and PEEK 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.