COC vs PMMA
Polymer · grade comparison
COC and PMMA are both polymer grades. PMMA is the stronger of the two: yield strength 68 MPa (9.86 ksi) against 60 MPa (8.7 ksi) for COC, about 13% more; tensile strength follows at 70 MPa (10.2 ksi) vs 63 MPa (9.14 ksi). In exchange, COC is the more ductile: elongation 5% versus 4.5% for PMMA. COC is lighter (1.02 g/cm³ vs 1.19 g/cm³ for PMMA) and COC runs hotter in service (110°C vs 70°C continuous). On the shop floor, PMMA machines more easily (very good vs good) and PMMA sits in a lower cost tier (budget, $) than COC (high, $$$$).
COCChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
PMMAChoose it when strength drives the design, or when the part is machined in volume.
COC vs PMMA: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all polymer grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all polymer grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Flexural Strength
Flexural Modulus
Izod Impact, Notched
Hardness, Rockwell M
Shear Modulus
Bulk Modulus
Compressive Strength
Compressive Modulus
Shear Strength
Fracture Toughness (K_IC)
Hardness, Shore D
Physical
Density and transition temperatures.
Density
Glass Transition (Tg)
Water Absorption (24 h)
Water Absorption (Saturation)
Refractive Index
Light Transmission
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Min Service Temperature
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Limiting Oxygen Index
Max Service Temperature (short-term)
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Volume Resistivity
Surface Resistivity
Same in both: Comparative Tracking Index (CTI) 600 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
UV / Weathering Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Polishability
Mold Shrinkage
Melt Flow Rate
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Typical Recycled Content
Embodied Water
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
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.
Manufacturing and finishing
| Capability | COC | PMMA |
|---|---|---|
| CNC machining | — | Yes |
| Sheet metal | — | Yes |
| Injection molding | — | Yes |
| Default condition | — | Extruded |
| Relative cost | $$$$ High | $ Budget |
| Min. machined wall | — | 0.5 mm |
| Best machined surface | — | Ra 0.8 µm |
| Chrome Plating (Plastic) | — | Yes |
| EMI Shielding Coating | — | Yes |
| Painting | — | Yes |
| Soft Touch Coating | — | Yes |
| Spray Painting | — | Yes |
| UV Coating | — | Yes |
COC vs PMMA — frequently asked
Is PMMA stronger than COC?
Yes. PMMA has a typical yield strength of 68 MPa (9.86 ksi) against 60 MPa (8.7 ksi) for COC — about 13% more. Tensile strength is 70 MPa (10.2 ksi) vs 63 MPa (9.14 ksi).
Which is cheaper, COC or PMMA?
PMMA is the lower-cost material: it sits in the budget tier ($) while COC is high ($$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which is easier to machine, COC or PMMA?
PMMA. Its machinability rates very good (70/100) against good (60/100) for COC; for welding the order is PMMA first (good, 55/100) then COC (fair, 50/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in COC 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.