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CPVC vs PVC-M

Polymer · grade comparison

CPVC and PVC-M are both polymer grades. CPVC is the stronger of the two: yield strength 52 MPa (7.54 ksi) against 44 MPa (6.38 ksi) for PVC-M, about 18% more; tensile strength follows at 55 MPa (7.98 ksi) vs 47 MPa (6.82 ksi). In exchange, PVC-M is the more ductile: elongation 100% versus 25% for CPVC. PVC-M is lighter (1.4 g/cm³ vs 1.54 g/cm³ for CPVC) and CPVC is stiffer (3 GPa vs 2.7 GPa). On the shop floor, PVC-M welds better (very good vs good) and PVC-M sits in a lower cost tier (budget, $) than CPVC (standard, $$).

CPVCChoose it when strength drives the design, or when the part sees heat.

PVC-MChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.

CPVC vs PVC-M: properties

CPVCPVC-M

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

3 GPa0.44 Msi
2.7 GPa0.39 Msi

Shear Modulus

1.1 GPa0.16 Msi
1 GPa0.15 Msi

Poisson's Ratio

0.38
0.39

Tensile Strength (Ultimate)

55 MPa8 ksi
47 MPa6.8 ksi

Yield Strength (0.2% offset)

52 MPa7.5 ksi
44 MPa6.4 ksi

Elongation at Break

25%
100%

Compressive Strength

75 MPa10.9 ksi
60 MPa8.7 ksi

Compressive Modulus

2.7 GPa0.39 Msi
2.6 GPa0.38 Msi

Flexural Strength

95 MPa13.8 ksi
72 MPa10.4 ksi

Flexural Modulus

3 GPa0.44 Msi
2.7 GPa0.38 Msi

Shear Strength

45 MPa6.5 ksi
35 MPa5.1 ksi

Izod Impact, Notched

90 J/m1.7 ft·lbf/in
600 J/m11.2 ft·lbf/in

Hardness, Shore D

82 Shore D
78 Shore D

Hardness, Rockwell R

118 HRR
108 HRR

Bulk Modulus

—
4 GPa0.61 Msi

Fracture Toughness (K_IC)

—
4.5 MPa·√m4.1 ksi·√in

Hardness, Rockwell M

—
68 HRM

Physical

Density and transition temperatures.

Density

1.54 g/cm³0.06 lb/in³
1.4 g/cm³0.05 lb/in³

Glass Transition (Tg)

115°C239 °F
78°C172 °F

Water Absorption (24 h)

0.04%
0.1%

Water Absorption (Saturation)

0.25%
0.35%

Refractive Index

1.55
1.54

Thermal

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

Thermal Conductivity

0.14 W/m·K0.08 BTU/hr·ft·°F
0.16 W/m·K0.09 BTU/hr·ft·°F

Specific Heat Capacity

950 J/kg·K0.23 BTU/lb·°F
980 J/kg·K0.23 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

68 µm/m·K37.8 µin/in·°F
75 µm/m·K41.7 µin/in·°F

Max Service Temperature (continuous)

93°C199 °F
60°C140 °F

Min Service Temperature

0°C32 °F
-20°C-4 °F

Heat Deflection Temp. @ 0.45 MPa

118°C244 °F
71°C160 °F

Heat Deflection Temp. @ 1.8 MPa

103°C217 °F
65°C149 °F

Vicat Softening Point (B50)

115°C239 °F
78°C172 °F

Limiting Oxygen Index

60%
38%

Max Service Temperature (short-term)

105°C221 °F
70°C158 °F

Electrical

Conductivity and insulation.

Dielectric Strength

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

Dielectric Constant (1 MHz)

3.4
3.1

Dissipation Factor (1 MHz)

0.014
0.016

Surface Resistivity

—
1×10¹⁴ Ω

Same in both: Electrical Resistivity 1×10¹³ Ω·m3.94×10²⁰ µΩ·in · Volume Resistivity 1×10¹⁵ Ω·cm · Comparative Tracking Index (CTI) 600 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

85 / 100
90 / 100

UV / Weathering Resistance

55 / 100
58 / 100

Manufacturability

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

Machinability

75 / 100
78 / 100

Weldability

65 / 100
80 / 100

Formability (cold)

55 / 100
60 / 100

Polishability

55 / 100
50 / 100

Mold Shrinkage

0.5%
0.3%

Processing Melt Temperature (typ.)

200°C392 °F
192°C378 °F

Mold Temperature (typ.)

55°C131 °F
40°C104 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

75 MJ/kg32,244 BTU/lb
68 MJ/kg29,235 BTU/lb

Embodied Carbon (primary production)

3 kg CO₂/kg
2.8 kg CO₂/kg

Embodied Water

180 L/kg21.6 gal/lb
130 L/kg15.6 gal/lb

Typical Recycled Content

0%
5%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

36 kN·m/kg
34 kN·m/kg

Modulus of Resilience

451 kJ/m³
359 kJ/m³

Same in both: Specific Stiffness (E / density) 1.9 MN·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 scalePVC-MCPVC

Manufacturing and finishing

CapabilityCPVCPVC-M
CNC machiningYes—
Sheet metalYes—
Injection moldingYes—
Default conditionUnfilled—
Relative cost$$ Standard$ Budget
Min. machined wall0.5 mm—
Best machined surfaceRa 0.8 µm—
Chrome Plating (Plastic)Yes—
EMI Shielding CoatingYes—
PaintingYes—
Soft Touch CoatingYes—
Spray PaintingYes—
UV CoatingYes—

CPVC vs PVC-M — frequently asked

Is CPVC stronger than PVC-M?

Yes. CPVC has a typical yield strength of 52 MPa (7.54 ksi) against 44 MPa (6.38 ksi) for PVC-M — about 18% more. Tensile strength is 55 MPa (7.98 ksi) vs 47 MPa (6.82 ksi).

Which is cheaper, CPVC or PVC-M?

PVC-M is the lower-cost material: it sits in the budget tier ($) while CPVC is standard ($$). 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, CPVC or PVC-M?

PVC-M. Its weldability rates very good (80/100) against good (65/100) for CPVC.

Ready to make it?

Upload a CAD file and FabDigit prices the part in CPVC and PVC-M 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.