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PC vs PMMA

Polymer · grade comparison

PC and PMMA are both polymer grades. PMMA is the stronger of the two: yield strength 68 MPa (9.86 ksi) against 63 MPa (9.14 ksi) for PC, about 8% more. In exchange, PC is the more ductile: elongation 110% versus 4.5% for PMMA, and PMMA is harder (89 Shore D vs 84 Shore D). PMMA is stiffer (3.2 GPa vs 2.4 GPa) and PC runs hotter in service (120°C vs 70°C continuous). On the shop floor, PC welds better (very good vs good).

PCChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

PMMAChoose it when strength drives the design.

PC vs PMMA: properties

PCPMMA

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

2.4 GPa0.34 Msi
3.2 GPa0.46 Msi

Shear Modulus

0.83 GPa0.12 Msi
1.2 GPa0.17 Msi

Bulk Modulus

4 GPa0.51 Msi
6 GPa0.81 Msi

Poisson's Ratio

0.38
0.37

Tensile Strength (Ultimate)

68 MPa9.9 ksi
70 MPa10.2 ksi

Yield Strength (0.2% offset)

63 MPa9.1 ksi
68 MPa9.9 ksi

Elongation at Break

110%
4.5%

Compressive Strength

80 MPa11.6 ksi
110 MPa16 ksi

Compressive Modulus

2.4 GPa0.35 Msi
3.1 GPa0.45 Msi

Flexural Strength

97 MPa14.1 ksi
100 MPa14.5 ksi

Flexural Modulus

2.4 GPa0.34 Msi
3.1 GPa0.45 Msi

Shear Strength

41 MPa5.9 ksi
60 MPa8.7 ksi

Fracture Toughness (K_IC)

2.2 MPa·√m2 ksi·√in
1.2 MPa·√m1.1 ksi·√in

Izod Impact, Notched

800 J/m15 ft·lbf/in
18 J/m0.34 ft·lbf/in

Hardness, Shore D

84 Shore D
89 Shore D

Hardness, Rockwell M

70 HRM
92 HRM

Hardness, Rockwell R

120 HRR
—

Physical

Density and transition temperatures.

Density

1.2 g/cm³0.04 lb/in³
1.19 g/cm³0.04 lb/in³

Glass Transition (Tg)

147°C297 °F
105°C221 °F

Water Absorption (24 h)

0.15%
0.3%

Water Absorption (Saturation)

0.35%
2%

Refractive Index

1.585
1.491

Light Transmission

88%
92%

Thermal

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

Thermal Conductivity

0.2 W/m·K0.12 BTU/hr·ft·°F
0.19 W/m·K0.11 BTU/hr·ft·°F

Specific Heat Capacity

1,200 J/kg·K0.29 BTU/lb·°F
1,470 J/kg·K0.35 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

67 µm/m·K37.2 µin/in·°F
70 µm/m·K38.9 µin/in·°F

Max Service Temperature (continuous)

120°C248 °F
70°C158 °F

Heat Deflection Temp. @ 0.45 MPa

138°C280 °F
96°C205 °F

Heat Deflection Temp. @ 1.8 MPa

129°C264 °F
88°C190 °F

Vicat Softening Point (B50)

146°C295 °F
105°C221 °F

Limiting Oxygen Index

26%
18%

Max Service Temperature (short-term)

145°C293 °F
95°C203 °F

Same in both: Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹⁴ Ω·m3.94×10²¹ µΩ·in
1×10¹³ Ω·m3.94×10²⁰ µΩ·in

Dielectric Strength

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

Dielectric Constant (1 MHz)

2.9
2.7

Dissipation Factor (1 MHz)

0.01
0.02

Volume Resistivity

1×10¹⁶ Ω·cm
1×10¹⁵ Ω·cm

Comparative Tracking Index (CTI)

250 V
600 V

Same in both: Surface Resistivity 1×10¹⁵ Ω

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

55 / 100
80 / 100

UV / Weathering Resistance

30 / 100
92 / 100

Manufacturability

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

Machinability

65 / 100
70 / 100

Weldability

70 / 100
55 / 100

Formability (cold)

75 / 100
45 / 100

Polishability

85 / 100
96 / 100

Mold Shrinkage

0.6%
0.5%

Melt Flow Rate

10 g/10 min
2 g/10 min

Processing Melt Temperature (typ.)

295°C563 °F
240°C464 °F

Mold Temperature (typ.)

90°C194 °F
70°C158 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

105 MJ/kg45,142 BTU/lb
101 MJ/kg43,422 BTU/lb

Embodied Carbon (primary production)

6.3 kg CO₂/kg
6.4 kg CO₂/kg

Embodied Water

250 L/kg30 gal/lb
280 L/kg33.6 gal/lb

Typical Recycled Content

5%
2%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

57 kN·m/kg
59 kN·m/kg

Specific Stiffness (E / density)

2 MN·m/kg
2.7 MN·m/kg

Modulus of Resilience

844 kJ/m³
723 kJ/m³

Same in both: 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 scalePCPMMA

Manufacturing and finishing

CapabilityPCPMMA
3D printingYes—
Default conditionUnfilledExtruded
Relative cost$ Budget$ Budget
Min. machined wall0.5 mm0.5 mm
Best machined surfaceRa 0.8 µmRa 0.8 µm
Conductive CoatingYes—
Dyeing (Nylon)Yes—
Primer CoatingYes—
Tinted CoatingYes—
Vacuum MetallizationYes—
Waterproof CoatingYes—

Both are offered for CNC machining, Sheet metal and Injection molding. They share 6 finishes: Chrome Plating (Plastic), EMI Shielding Coating, Painting, Soft Touch Coating, Spray Painting, UV Coating.

PC vs PMMA — frequently asked

Is PMMA stronger than PC?

Yes. PMMA has a typical yield strength of 68 MPa (9.86 ksi) against 63 MPa (9.14 ksi) for PC — about 8% more. Tensile strength is 70 MPa (10.2 ksi) vs 68 MPa (9.86 ksi).

Which is cheaper, PC or PMMA?

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 is easier to machine, PC or PMMA?

PMMA. Its machinability rates very good (70/100) against good (65/100) for PC; for welding the order is PC first (very good, 70/100) then PMMA (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in PC and PMMA 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.