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PC-MF vs PC-Si

Polymer · grade comparison

PC-MF and PC-Si are both polymer grades. Both yield at about 60 MPa — strength does not separate them. PC-Si is the more ductile: elongation 120% versus 10% for PC-MF, and PC-MF is harder (85 Shore D vs 80 Shore D). PC-Si is lighter (1.19 g/cm³ vs 1.35 g/cm³ for PC-MF) and PC-MF is stiffer (3.8 GPa vs 2.2 GPa). On the shop floor, PC-MF sits in a lower cost tier (standard, $$) than PC-Si (premium, $$$).

PC-MFChoose it when cost is the deciding factor.

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

PC-MF vs PC-Si: properties

PC-MFPC-Si

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

3.8 GPa0.55 Msi
2.2 GPa0.32 Msi

Shear Modulus

1.4 GPa0.2 Msi
0.8 GPa0.12 Msi

Bulk Modulus

5 GPa0.73 Msi
3 GPa0.49 Msi

Tensile Strength (Ultimate)

62 MPa9 ksi
60 MPa8.7 ksi

Yield Strength (0.2% offset)

60 MPa8.7 ksi
58 MPa8.4 ksi

Elongation at Break

10%
120%

Compressive Strength

88 MPa12.8 ksi
72 MPa10.4 ksi

Compressive Modulus

3.2 GPa0.46 Msi
2.1 GPa0.3 Msi

Flexural Strength

100 MPa14.5 ksi
88 MPa12.8 ksi

Flexural Modulus

3.7 GPa0.54 Msi
2.2 GPa0.32 Msi

Shear Strength

45 MPa6.5 ksi
40 MPa5.8 ksi

Fracture Toughness (K_IC)

2.2 MPa·√m2 ksi·√in
—

Izod Impact, Notched

110 J/m2.1 ft·lbf/in
850 J/m15.9 ft·lbf/in

Hardness, Shore D

85 Shore D
80 Shore D

Hardness, Rockwell M

78 HRM
68 HRM

Hardness, Rockwell R

120 HRR
118 HRR

Same in both: Poisson's Ratio 0.38

Physical

Density and transition temperatures.

Density

1.35 g/cm³0.05 lb/in³
1.19 g/cm³0.04 lb/in³

Glass Transition (Tg)

147°C297 °F
143°C289 °F

Refractive Index

—
1.585

Same in both: Water Absorption (24 h) 0.15% · Water Absorption (Saturation) 0.35%

Thermal

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

Thermal Conductivity

0.27 W/m·K0.16 BTU/hr·ft·°F
0.2 W/m·K0.12 BTU/hr·ft·°F

Specific Heat Capacity

1,150 J/kg·K0.27 BTU/lb·°F
1,200 J/kg·K0.29 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

50 µm/m·K27.8 µin/in·°F
68 µm/m·K37.8 µin/in·°F

Max Service Temperature (continuous)

120°C248 °F
115°C239 °F

Min Service Temperature

-40°C-40 °F
-60°C-76 °F

Heat Deflection Temp. @ 0.45 MPa

142°C288 °F
132°C270 °F

Heat Deflection Temp. @ 1.8 MPa

132°C270 °F
120°C248 °F

Vicat Softening Point (B50)

146°C295 °F
142°C288 °F

Limiting Oxygen Index

27%
32%

Max Service Temperature (short-term)

140°C284 °F
145°C293 °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

22 kV/mm559 V/mil
25 kV/mm635 V/mil

Dielectric Constant (1 MHz)

3.3
2.9

Dissipation Factor (1 MHz)

0.011
0.01

Volume Resistivity

1×10¹⁵ Ω·cm
1×10¹⁶ Ω·cm

Same in both: Surface Resistivity 1×10¹⁵ Ω · Comparative Tracking Index (CTI) 250 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

68 / 100
75 / 100

UV / Weathering Resistance

35 / 100
40 / 100

Manufacturability

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

Machinability

62 / 100
60 / 100

Weldability

65 / 100
70 / 100

Formability (cold)

25 / 100
60 / 100

Polishability

30 / 100
80 / 100

Mold Shrinkage

0.45%
0.6%

Melt Flow Rate

10 g/10 min
8 g/10 min

Processing Melt Temperature (typ.)

295°C563 °F
290°C554 °F

Same in both: Mold Temperature (typ.) 90°C194 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

90 MJ/kg38,693 BTU/lb
112 MJ/kg48,151 BTU/lb

Embodied Carbon (primary production)

5.5 kg CO₂/kg
7.8 kg CO₂/kg

Embodied Water

200 L/kg24 gal/lb
250 L/kg30 gal/lb

Typical Recycled Content

15%
0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

46 kN·m/kg
50 kN·m/kg

Specific Stiffness (E / density)

2.8 MN·m/kg
1.8 MN·m/kg

Modulus of Resilience

474 kJ/m³
765 kJ/m³

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 scalePC-SiPC-MF

Manufacturing and finishing

CapabilityPC-MFPC-Si
Default condition——
Relative cost$$ Standard$$$ Premium
Min. machined wall——
Best machined surface——

PC-MF vs PC-Si — frequently asked

What is the difference between PC-MF and PC-Si?

PC-MF and PC-Si are both polymer grades. Both yield at about 60 MPa — strength does not separate them. PC-Si is the more ductile: elongation 120% versus 10% for PC-MF, and PC-MF is harder (85 Shore D vs 80 Shore D).

Which is cheaper, PC-MF or PC-Si?

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

Which welds better, PC-MF or PC-Si?

PC-Si. Its weldability rates very good (70/100) against good (65/100) for PC-MF.

Ready to make it?

Upload a CAD file and FabDigit prices the part in PC-MF and PC-Si 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.