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PCTA vs PET

Polymer · grade comparison

PCTA and PET are both polymer grades. PET is the stronger of the two: yield strength 80 MPa (11.6 ksi) against 49 MPa (7.11 ksi) for PCTA, about 63% more; tensile strength follows at 82 MPa (11.9 ksi) vs 50 MPa (7.25 ksi). In exchange, PCTA is the more ductile: elongation 250% versus 20% for PET, and PET is harder (85 Shore D vs 78 Shore D). PCTA is lighter (1.2 g/cm³ vs 1.39 g/cm³ for PET) and PET is stiffer (3.1 GPa vs 2 GPa). On the shop floor, PET machines more easily (very good vs good), PCTA welds better (excellent vs fair), and PET sits in a lower cost tier (standard, $$) than PCTA (premium, $$$).

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

PETChoose it when strength drives the design, or when the part sees heat.

PCTA vs PET: properties

PCTAPET

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

2 GPa0.29 Msi
3.1 GPa0.45 Msi

Shear Modulus

0.75 GPa0.11 Msi
1.1 GPa0.16 Msi

Bulk Modulus

3 GPa0.41 Msi
5 GPa0.65 Msi

Poisson's Ratio

0.38
0.4

Tensile Strength (Ultimate)

50 MPa7.3 ksi
82 MPa11.9 ksi

Yield Strength (0.2% offset)

49 MPa7.1 ksi
80 MPa11.6 ksi

Elongation at Break

250%
20%

Compressive Strength

60 MPa8.7 ksi
100 MPa14.5 ksi

Compressive Modulus

1.9 GPa0.28 Msi
3 GPa0.44 Msi

Flexural Strength

70 MPa10.2 ksi
120 MPa17.4 ksi

Flexural Modulus

2 GPa0.29 Msi
3.1 GPa0.45 Msi

Shear Strength

40 MPa5.8 ksi
55 MPa8 ksi

Izod Impact, Notched

110 J/m2.1 ft·lbf/in
40 J/m0.75 ft·lbf/in

Hardness, Shore D

78 Shore D
85 Shore D

Hardness, Rockwell R

110 HRR
120 HRR

Fracture Toughness (K_IC)

—
4 MPa·√m3.6 ksi·√in

Hardness, Rockwell M

—
94 HRM

Physical

Density and transition temperatures.

Density

1.2 g/cm³0.04 lb/in³
1.39 g/cm³0.05 lb/in³

Glass Transition (Tg)

88°C190 °F
79°C174 °F

Water Absorption (24 h)

0.13%
0.11%

Refractive Index

1.567
1.575

Light Transmission

89%
88%

Melting Temperature (Tm)

—
255°C491 °F

Same in both: Water Absorption (Saturation) 0.5%

Thermal

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

Thermal Conductivity

0.19 W/m·K0.11 BTU/hr·ft·°F
0.25 W/m·K0.14 BTU/hr·ft·°F

Specific Heat Capacity

1,300 J/kg·K0.31 BTU/lb·°F
1,150 J/kg·K0.27 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

68 µm/m·K37.8 µin/in·°F
65 µm/m·K36.1 µin/in·°F

Max Service Temperature (continuous)

65°C149 °F
100°C212 °F

Min Service Temperature

-40°C-40 °F
-20°C-4 °F

Heat Deflection Temp. @ 0.45 MPa

70°C158 °F
115°C239 °F

Heat Deflection Temp. @ 1.8 MPa

64°C147 °F
80°C176 °F

Vicat Softening Point (B50)

84°C183 °F
180°C356 °F

Limiting Oxygen Index

24%
22%

Max Service Temperature (short-term)

85°C185 °F
150°C302 °F

Electrical

Conductivity and insulation.

Dielectric Strength

18 kV/mm457 V/mil
22 kV/mm559 V/mil

Dielectric Constant (1 MHz)

2.9
3.2

Surface Resistivity

1×10¹⁶ Ω
1×10¹⁵ Ω

Comparative Tracking Index (CTI)

—
600 V

Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Dissipation Factor (1 MHz) 0.018 · Volume Resistivity 1×10¹⁶ Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

72 / 100
70 / 100

UV / Weathering Resistance

48 / 100
30 / 100

Manufacturability

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

Machinability

62 / 100
78 / 100

Weldability

85 / 100
45 / 100

Formability (cold)

90 / 100
50 / 100

Polishability

80 / 100
60 / 100

Mold Shrinkage

0.35%
2%

Processing Melt Temperature (typ.)

255°C491 °F
280°C536 °F

Mold Temperature (typ.)

25°C77 °F
135°C275 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

86 MJ/kg36,973 BTU/lb
82 MJ/kg35,254 BTU/lb

Embodied Carbon (primary production)

4.1 kg CO₂/kg
2.8 kg CO₂/kg

Embodied Water

130 L/kg15.6 gal/lb
120 L/kg14.4 gal/lb

Typical Recycled Content

0%
25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

42 kN·m/kg
59 kN·m/kg

Specific Stiffness (E / density)

1.7 MN·m/kg
2.2 MN·m/kg

Modulus of Resilience

600 kJ/m³
1,032 kJ/m³

Thermal Diffusivity

0.1 mm²/s
0.2 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 scalePETPCTA

Manufacturing and finishing

CapabilityPCTAPET
CNC machining—Yes
Sheet metal—Yes
Injection molding—Yes
Default condition—Unfilled
Relative cost$$$ Premium$$ Standard
Min. machined wall—0.5 mm
Best machined surface—Ra 0.8 µm
Chrome Plating (Plastic)—Yes
EMI Shielding Coating—Yes
Painting—Yes
Soft Touch Coating—Yes
Spray Painting—Yes
UV Coating—Yes

PCTA vs PET — frequently asked

Is PET stronger than PCTA?

Yes. PET has a typical yield strength of 80 MPa (11.6 ksi) against 49 MPa (7.11 ksi) for PCTA — about 63% more. Tensile strength is 82 MPa (11.9 ksi) vs 50 MPa (7.25 ksi).

Which is cheaper, PCTA or PET?

PET is the lower-cost material: it sits in the standard tier ($$) while PCTA is premium ($$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, PCTA or PET?

PET. Its machinability rates very good (78/100) against good (62/100) for PCTA; for welding the order is PCTA first (excellent, 85/100) then PET (fair, 45/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in PCTA and PET 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.