PMMA vs PX521
Polymer · grade comparison
PMMA and PX521 are both polymer grades, both clear plastic. PMMA is the more ductile: elongation 4.5% versus 4% for PX521. PX521 runs hotter in service (80°C vs 70°C continuous). On the shop floor, PMMA welds better (good vs poor) and PMMA sits in a lower cost tier (budget, $) than PX521 (standard, $$).
PMMAChoose it when the part is bent, formed or impact-loaded, or when it will be welded.
PX521Choose it when the part sees heat.
PMMA vs PX521: 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.
Shear Modulus
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Modulus
Flexural Strength
Fracture Toughness (K_IC)
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell M
Same in both: Elastic (Young's) Modulus 3.2 GPa0.46 Msi · Poisson's Ratio 0.37 · Compressive Strength 110 MPa16 ksi · Flexural Modulus 3.1 GPa0.45 Msi · Shear Strength 60 MPa8.7 ksi
Physical
Density and transition temperatures.
Glass Transition (Tg)
Refractive Index
Same in both: Density 1.19 g/cm³0.04 lb/in³ · Water Absorption (24 h) 0.3% · Water Absorption (Saturation) 2% · Light Transmission 92%
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Limiting Oxygen Index
Same in both: Thermal Conductivity 0.19 W/m·K0.11 BTU/hr·ft·°F · Specific Heat Capacity 1,470 J/kg·K0.35 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 70 µm/m·K38.9 µin/in·°F · Min Service Temperature -40°C-40 °F · Max Service Temperature (short-term) 95°C203 °F
Electrical
Conductivity and insulation.
Dielectric Strength
Same in both: Electrical Resistivity 1×10¹³ Ω·m3.94×10²⁰ µΩ·in · Dielectric Constant (1 MHz) 2.7 · Dissipation Factor (1 MHz) 0.02 · Volume Resistivity 1×10¹⁵ Ω·cm · Surface Resistivity 1×10¹⁵ Ω · Comparative Tracking Index (CTI) 600 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: UV / Weathering Resistance 92 / 100
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)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Same in both: Specific Stiffness (E / density) 2.7 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.
Manufacturing and finishing
| Capability | PMMA | PX521 |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| 3D printing | — | Yes |
| Default condition | Extruded | UV Resistant |
| Relative cost | $ Budget | $$ Standard |
| Min. machined wall | 0.5 mm | — |
| Best machined surface | Ra 0.8 µm | — |
| Conductive Coating | — | Yes |
| Dyeing (Nylon) | — | Yes |
| Primer Coating | — | Yes |
| Tinted Coating | — | Yes |
| Vacuum Metallization | — | Yes |
| Waterproof Coating | — | Yes |
Both are offered for Injection molding. They share 6 finishes: Chrome Plating (Plastic), EMI Shielding Coating, Painting, Soft Touch Coating, Spray Painting, UV Coating.
PMMA vs PX521 — frequently asked
What is the difference between PMMA and PX521?
PMMA and PX521 are both polymer grades, both clear plastic. PMMA is the more ductile: elongation 4.5% versus 4% for PX521. PX521 runs hotter in service (80°C vs 70°C continuous).
Which is cheaper, PMMA or PX521?
PMMA is the lower-cost material: it sits in the budget tier ($) while PX521 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 is easier to machine, PMMA or PX521?
PX521, by a small margin. Both rate very good for machinability — 75/100 against 70/100 for PMMA; for welding the order is PMMA first (good, 55/100) then PX521 (poor, 30/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in PMMA and PX521 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.