FabDigit

PPS vs PI and 2 more: properties

PPSPIPEEKPEKK

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

3.8 GPa0.55 Msi
3 GPa0.44 Msi
3.7 GPa0.54 Msi
3.9 GPa0.57 Msi

Shear Modulus

1.4 GPa0.2 Msi
1.1 GPa0.16 Msi
1.3 GPa0.19 Msi
1.4 GPa0.2 Msi

Poisson's Ratio

0.37
0.41
0.4
0.4

Tensile Strength (Ultimate)

78 MPa11.3 ksi
86 MPa12.5 ksi
100 MPa14.5 ksi
95 MPa13.8 ksi

Yield Strength (0.2% offset)

75 MPa10.9 ksi
100 MPa14.5 ksi
95 MPa13.8 ksi

Elongation at Break

5%
7.5%
30%
8%

Compressive Strength

120 MPa17.4 ksi
130 MPa18.9 ksi
130 MPa18.9 ksi
130 MPa18.9 ksi

Compressive Modulus

3.5 GPa0.51 Msi
2.9 GPa0.42 Msi
3.6 GPa0.52 Msi
3.5 GPa0.51 Msi

Flexural Strength

130 MPa18.9 ksi
110 MPa16 ksi
165 MPa23.9 ksi
150 MPa21.8 ksi

Flexural Modulus

3.9 GPa0.57 Msi
3.1 GPa0.45 Msi
4 GPa0.58 Msi
3.9 GPa0.57 Msi

Shear Strength

65 MPa9.4 ksi
80 MPa11.6 ksi
55 MPa8 ksi
65 MPa9.4 ksi

Izod Impact, Notched

25 J/m0.47 ft·lbf/in
43 J/m0.81 ft·lbf/in
75 J/m1.4 ft·lbf/in
50 J/m0.94 ft·lbf/in

Hardness, Shore D

88 Shore D
88 Shore D
86 Shore D
86 Shore D

Hardness, Rockwell M

95 HRM
105 HRM
99 HRM
100 HRM

Hardness, Rockwell R

123 HRR
126 HRR

Bulk Modulus

6 GPa0.8 Msi
6 GPa0.87 Msi
7 GPa0.94 Msi

Fracture Toughness (K_IC)

2 MPa·√m1.8 ksi·√in
3.5 MPa·√m3.2 ksi·√in
3.5 MPa·√m3.2 ksi·√in

Physical

Density and transition temperatures.

Density

1.35 g/cm³0.05 lb/in³
1.43 g/cm³0.05 lb/in³
1.3 g/cm³0.05 lb/in³
1.3 g/cm³0.05 lb/in³

Melting Temperature (Tm)

280°C536 °F
343°C649 °F
332°C630 °F

Glass Transition (Tg)

88°C190 °F
385°C725 °F
143°C289 °F
162°C324 °F

Water Absorption (24 h)

0.03%
0.3%
0.12%
0.15%

Water Absorption (Saturation)

0.1%
1.2%
0.45%
0.5%

Refractive Index

1.7

Thermal

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

Thermal Conductivity

0.29 W/m·K0.17 BTU/hr·ft·°F
0.29 W/m·K0.17 BTU/hr·ft·°F
0.25 W/m·K0.14 BTU/hr·ft·°F
0.26 W/m·K0.15 BTU/hr·ft·°F

Specific Heat Capacity

1,000 J/kg·K0.24 BTU/lb·°F
1,130 J/kg·K0.27 BTU/lb·°F
1,340 J/kg·K0.32 BTU/lb·°F
1,050 J/kg·K0.25 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

52 µm/m·K28.9 µin/in·°F
52 µm/m·K28.9 µin/in·°F
47 µm/m·K26.1 µin/in·°F
48 µm/m·K26.7 µin/in·°F

Max Service Temperature (continuous)

220°C428 °F
260°C500 °F
250°C482 °F
240°C464 °F

Min Service Temperature

-40°C-40 °F
-240°C-400 °F
-60°C-76 °F
-60°C-76 °F

Heat Deflection Temp. @ 0.45 MPa

240°C464 °F
400°C752 °F
315°C599 °F
175°C347 °F

Heat Deflection Temp. @ 1.8 MPa

110°C230 °F
360°C680 °F
152°C306 °F
160°C320 °F

Limiting Oxygen Index

47%
45%
35%
40%

Max Service Temperature (short-term)

260°C500 °F
480°C896 °F
300°C572 °F
300°C572 °F

Vicat Softening Point (B50)

315°C599 °F

Electrical

Conductivity and insulation.

Dielectric Strength

18 kV/mm457 V/mil
22 kV/mm559 V/mil
21 kV/mm533 V/mil
22 kV/mm559 V/mil

Dielectric Constant (1 MHz)

3.1
3.5
3.2
3.3

Dissipation Factor (1 MHz)

0.0013
0.0034
0.003
0.004

Comparative Tracking Index (CTI)

175 V
150 V
175 V

Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Volume Resistivity 1×10¹⁶ Ω·cm · Surface Resistivity 1×10¹⁵ Ω

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

92 / 100
85 / 100
90 / 100
92 / 100

UV / Weathering Resistance

35 / 100
60 / 100
45 / 100
45 / 100

Manufacturability

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

Machinability

60 / 100
65 / 100
70 / 100
60 / 100

Weldability

30 / 100
5 / 100
45 / 100
55 / 100

Formability (cold)

15 / 100
15 / 100
30 / 100
35 / 100

Polishability

60 / 100
60 / 100
70 / 100
60 / 100

Mold Shrinkage

1.2%
1.2%
1.2%

Processing Melt Temperature (typ.)

320°C608 °F
380°C716 °F
380°C716 °F

Mold Temperature (typ.)

140°C284 °F
180°C356 °F
200°C392 °F

Melt Flow Rate

3 g/10 min

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

115 MJ/kg49,441 BTU/lb
290 MJ/kg124,678 BTU/lb
290 MJ/kg124,678 BTU/lb
330 MJ/kg141,875 BTU/lb

Embodied Carbon (primary production)

6.2 kg CO₂/kg
13 kg CO₂/kg
15 kg CO₂/kg
18 kg CO₂/kg

Embodied Water

300 L/kg35.9 gal/lb
600 L/kg71.9 gal/lb
450 L/kg53.9 gal/lb
500 L/kg59.9 gal/lb

Typical Recycled Content

2%
0%
0%
0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

58 kN·m/kg
60 kN·m/kg
77 kN·m/kg
73 kN·m/kg

Specific Stiffness (E / density)

2.8 MN·m/kg
2.1 MN·m/kg
2.8 MN·m/kg
3 MN·m/kg

Thermal Diffusivity

0.2 mm²/s
0.2 mm²/s
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 scalePIPEEKPEKKPPS

Manufacturing and finishing

CapabilityPPSPIPEEKPEKK
CNC machiningYesYesYes
Sheet metalYesYesYes
Injection moldingYesYesYes
3D printingYesYes
Default conditionUnfilledUnfilledVirginUnfilled
Relative cost$$$$$ Specialty$$$$$ Specialty$$$$$ Specialty$$$$$ Specialty
Min. machined wall0.5 mm0.5 mm0.8 mm
Best machined surfaceRa 0.8 µmRa 0.8 µmRa 0.8 µm
Chrome Plating (Plastic)YesYesYes
Conductive CoatingYesYes
Dyeing (Nylon)YesYes
Primer CoatingYesYes
Spray PaintingYesYesYes
Tinted CoatingYesYes
Vacuum MetallizationYesYes
Waterproof CoatingYesYes

They share 4 finishes: EMI Shielding Coating, Painting, Soft Touch Coating, UV Coating.

Ready to make it?

Upload a CAD file and FabDigit prices the part in PPS and PI 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.