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PP-C vs PP-R

Polymer · grade comparison

PP-C and PP-R are both polymer grades. Both yield at about 25 MPa — strength does not separate them. PP-R is the more ductile: elongation 600% versus 350% for PP-C. PP-C is stiffer (1.1 GPa vs 0.85 GPa) and PP-C runs hotter in service (95°C vs 70°C continuous).

PP-CChoose it when the part sees heat.

PP-RChoose it when the part is bent, formed or impact-loaded.

PP-C vs PP-R: properties

PP-CPP-R

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

1.1 GPa0.16 Msi
0.85 GPa0.12 Msi

Shear Modulus

0.4 GPa0.06 Msi
0.3 GPa0.04 Msi

Bulk Modulus

3 GPa0.48 Msi
3 GPa0.42 Msi

Elongation at Break

350%
600%

Compressive Strength

32 MPa4.6 ksi
40 MPa5.8 ksi

Compressive Modulus

1 GPa0.15 Msi
0.9 GPa0.13 Msi

Flexural Modulus

1.1 GPa0.16 Msi
0.85 GPa0.12 Msi

Shear Strength

20 MPa2.9 ksi
18 MPa2.6 ksi

Fracture Toughness (K_IC)

3.8 MPa·√m3.5 ksi·√in
—

Izod Impact, Notched

250 J/m4.7 ft·lbf/in
80 J/m1.5 ft·lbf/in

Hardness, Shore D

67 Shore D
65 Shore D

Hardness, Rockwell R

88 HRR
85 HRR

Same in both: Poisson's Ratio 0.43 · Tensile Strength (Ultimate) 26 MPa3.8 ksi · Yield Strength (0.2% offset) 25 MPa3.6 ksi · Flexural Strength 30 MPa4.4 ksi

Physical

Density and transition temperatures.

Density

0.9 g/cm³0.03 lb/in³
0.91 g/cm³0.03 lb/in³

Melting Temperature (Tm)

164°C327 °F
148°C298 °F

Glass Transition (Tg)

-18°C-0.4 °F
-12°C10 °F

Same in both: Water Absorption (24 h) 0.02% · Water Absorption (Saturation) 0.1% · Refractive Index 1.49

Thermal

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

Thermal Conductivity

0.2 W/m·K0.12 BTU/hr·ft·°F
0.24 W/m·K0.14 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

110 µm/m·K61.1 µin/in·°F
150 µm/m·K83.3 µin/in·°F

Max Service Temperature (continuous)

95°C203 °F
70°C158 °F

Min Service Temperature

-35°C-31 °F
-10°C14 °F

Heat Deflection Temp. @ 0.45 MPa

88°C190 °F
80°C176 °F

Heat Deflection Temp. @ 1.8 MPa

55°C131 °F
52°C126 °F

Vicat Softening Point (B50)

88°C190 °F
80°C176 °F

Limiting Oxygen Index

18%
18%

Max Service Temperature (short-term)

120°C248 °F
95°C203 °F

Same in both: Specific Heat Capacity 1,900 J/kg·K0.45 BTU/lb·°F

Electrical

Conductivity and insulation.

Dielectric Strength

25 kV/mm635 V/mil
27 kV/mm686 V/mil

Dielectric Constant (1 MHz)

2.25
2.3

Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Dissipation Factor (1 MHz) 4×10⁻⁴ · Volume Resistivity 1×10¹⁶ Ω·cm · Surface Resistivity 1×10¹⁵ Ω · Comparative Tracking Index (CTI) 600 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

UV / Weathering Resistance

25 / 100
20 / 100

Same in both: Corrosion Resistance 90 / 100

Manufacturability

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

Machinability

65 / 100
62 / 100

Weldability

88 / 100
95 / 100

Formability (cold)

60 / 100
70 / 100

Polishability

40 / 100
45 / 100

Mold Shrinkage

1.5%
1.6%

Melt Flow Rate

12 g/10 min
0.3 g/10 min

Processing Melt Temperature (typ.)

230°C446 °F
215°C419 °F

Same in both: Mold Temperature (typ.) 40°C104 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Water

90 L/kg10.8 gal/lb
60 L/kg7.2 gal/lb

Typical Recycled Content

5%
0%

Same in both: Embodied Energy (primary production) 78 MJ/kg33,534 BTU/lb · Embodied Carbon (primary production) 2 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Stiffness (E / density)

1.2 MN·m/kg
0.9 MN·m/kg

Modulus of Resilience

284 kJ/m³
368 kJ/m³

Same in both: Specific Strength (UTS / density) 29 kN·m/kg · Thermal Diffusivity 0.1 mm²/s · 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 scalePP-CPP-R

Manufacturing and finishing

CapabilityPP-CPP-R
Default condition——
Relative cost$ Budget$ Budget
Min. machined wall——
Best machined surface——

PP-C vs PP-R — frequently asked

What is the difference between PP-C and PP-R?

PP-C and PP-R are both polymer grades. Both yield at about 25 MPa — strength does not separate them. PP-R is the more ductile: elongation 600% versus 350% for PP-C.

Which is cheaper, PP-C or PP-R?

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

Which welds better, PP-C or PP-R?

PP-R. Its weldability rates excellent (95/100) against excellent (88/100) for PP-C.

Ready to make it?

Upload a CAD file and FabDigit prices the part in PP-C and PP-R 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.