PMMA vs RTPU
Polymer · grade comparison
PMMA and RTPU are both polymer grades. PMMA is the stronger of the two: yield strength 68 MPa (9.86 ksi) against 52 MPa (7.54 ksi) for RTPU, about 31% more; tensile strength follows at 70 MPa (10.2 ksi) vs 58 MPa (8.41 ksi). In exchange, RTPU is the more ductile: elongation 140% versus 4.5% for PMMA, and PMMA is harder (89 Shore D vs 78 Shore D). PMMA is stiffer (3.2 GPa vs 2.1 GPa) and RTPU runs hotter in service (80°C vs 70°C continuous). On the shop floor, PMMA machines more easily (very good vs good), RTPU welds better (very good vs good), and PMMA sits in a lower cost tier (budget, $) than RTPU (premium, $$$).
PMMAChoose it when strength drives the design, or when the part is machined in volume.
RTPUChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
PMMA vs RTPU: 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
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Compressive Modulus
Flexural Strength
Flexural Modulus
Shear Strength
Fracture Toughness (K_IC)
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell M
Hardness, Rockwell R
Physical
Density and transition temperatures.
Density
Glass Transition (Tg)
Water Absorption (Saturation)
Refractive Index
Light Transmission
Same in both: Water Absorption (24 h) 0.3%
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)
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Limiting Oxygen Index
Max Service Temperature (short-term)
Same in both: Min Service Temperature -40°C-40 °F
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).
UV / Weathering Resistance
Same in both: Corrosion Resistance 80 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Polishability
Melt Flow Rate
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Same in both: Mold Shrinkage 0.5%
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)
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 | PMMA | RTPU |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| Injection molding | Yes | — |
| Default condition | Extruded | — |
| Relative cost | $ Budget | $$$ Premium |
| 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 | — |
PMMA vs RTPU — frequently asked
Is PMMA stronger than RTPU?
Yes. PMMA has a typical yield strength of 68 MPa (9.86 ksi) against 52 MPa (7.54 ksi) for RTPU — about 31% more. Tensile strength is 70 MPa (10.2 ksi) vs 58 MPa (8.41 ksi).
Which is cheaper, PMMA or RTPU?
PMMA is the lower-cost material: it sits in the budget tier ($) while RTPU 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 is easier to machine, PMMA or RTPU?
PMMA. Its machinability rates very good (70/100) against good (55/100) for RTPU; for welding the order is RTPU first (very good, 70/100) then PMMA (good, 55/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in PMMA and RTPU 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.