mPP vs PP-R
Polymer · grade comparison
mPP and PP-R are both polymer grades. mPP is the stronger of the two: yield strength 33 MPa (4.79 ksi) against 25 MPa (3.63 ksi) for PP-R, about 32% more; tensile strength follows at 35 MPa (5.08 ksi) vs 26 MPa (3.77 ksi). In exchange, PP-R is the more ductile: elongation 600% versus 400% for mPP. MPP is stiffer (1.3 GPa vs 0.85 GPa) and mPP runs hotter in service (95°C vs 70°C continuous). On the shop floor, PP-R welds better (95 vs 85 out of 100) and PP-R sits in a lower cost tier (budget, $) than mPP (standard, $$).
mPPChoose it when strength drives the design, or when the part sees heat.
PP-RChoose it when the part is bent, formed or impact-loaded, or when it will be welded.
mPP vs PP-R: 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 Modulus
Flexural Strength
Flexural Modulus
Shear Strength
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell R
Same in both: Compressive Strength 40 MPa5.8 ksi
Physical
Density and transition temperatures.
Density
Melting Temperature (Tm)
Glass Transition (Tg)
Water Absorption (24 h)
Water Absorption (Saturation)
Light Transmission
Same in both: Refractive Index 1.49
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)
Max Service Temperature (short-term)
Same in both: Limiting Oxygen Index 18%
Electrical
Conductivity and insulation.
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Surface Resistivity
Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Volume Resistivity 1×10¹⁶ Ω·cm · Comparative Tracking Index (CTI) 600 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
UV / Weathering Resistance
Same in both: Corrosion Resistance 90 / 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.
Same in both: Embodied Energy (primary production) 78 MJ/kg33,534 BTU/lb · Embodied Carbon (primary production) 2 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 0%
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 | mPP | PP-R |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$ Standard | $ Budget |
| Min. machined wall | — | — |
| Best machined surface | — | — |
mPP vs PP-R — frequently asked
Is mPP stronger than PP-R?
Yes. mPP has a typical yield strength of 33 MPa (4.79 ksi) against 25 MPa (3.63 ksi) for PP-R — about 32% more. Tensile strength is 35 MPa (5.08 ksi) vs 26 MPa (3.77 ksi).
Which is cheaper, mPP or PP-R?
PP-R is the lower-cost material: it sits in the budget tier ($) while mPP 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, mPP or PP-R?
PP-R. Its weldability rates excellent (95/100) against excellent (85/100) for mPP.
Ready to make it?
Upload a CAD file and FabDigit prices the part in mPP and PP-R 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.