FabDigit

PI vs PPS and 2 more: properties

PIPPSPEEKPEKK

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

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

Shear Modulus

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

Bulk Modulus

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

Poisson's Ratio

0.41
0.37
0.4
0.4

Tensile Strength (Ultimate)

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

Elongation at Break

7.5%
5%
30%
8%

Compressive Strength

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

Compressive Modulus

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

Flexural Strength

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

Flexural Modulus

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

Shear Strength

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

Fracture Toughness (K_IC)

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

Izod Impact, Notched

43 J/m0.81 ft·lbf/in
25 J/m0.47 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

105 HRM
95 HRM
99 HRM
100 HRM

Yield Strength (0.2% offset)

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

Hardness, Rockwell R

123 HRR
126 HRR

Physical

Density and transition temperatures.

Density

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

Glass Transition (Tg)

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

Water Absorption (24 h)

0.3%
0.03%
0.12%
0.15%

Water Absorption (Saturation)

1.2%
0.1%
0.45%
0.5%

Refractive Index

1.7

Melting Temperature (Tm)

280°C536 °F
343°C649 °F
332°C630 °F

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

1,130 J/kg·K0.27 BTU/lb·°F
1,000 J/kg·K0.24 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)

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

Min Service Temperature

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

Heat Deflection Temp. @ 0.45 MPa

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

Heat Deflection Temp. @ 1.8 MPa

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

Limiting Oxygen Index

45%
47%
35%
40%

Max Service Temperature (short-term)

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

Vicat Softening Point (B50)

315°C599 °F

Electrical

Conductivity and insulation.

Dielectric Strength

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

Dielectric Constant (1 MHz)

3.5
3.1
3.2
3.3

Dissipation Factor (1 MHz)

0.0034
0.0013
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

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

UV / Weathering Resistance

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

Manufacturability

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

Machinability

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

Weldability

5 / 100
30 / 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)

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

Embodied Carbon (primary production)

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

Embodied Water

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

Typical Recycled Content

0%
2%
0%
0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

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

Specific Stiffness (E / density)

2.1 MN·m/kg
2.8 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

CapabilityPIPPSPEEKPEKK
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 PI and PPS 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.