PMMA-HI vs PMMA-HR
Polymer · grade comparison
PMMA-HI and PMMA-HR are both polymer grades. PMMA-HR is the stronger of the two: yield strength 72 MPa (10.4 ksi) against 48 MPa (6.96 ksi) for PMMA-HI, about 50% more; tensile strength follows at 74 MPa (10.7 ksi) vs 50 MPa (7.25 ksi). In exchange, PMMA-HI is the more ductile: elongation 30% versus 3.5% for PMMA-HR. PMMA-HR is stiffer (3.3 GPa vs 2.2 GPa) and PMMA-HR runs hotter in service (95°C vs 72°C continuous). On the shop floor, PMMA-HI machines more easily (very good vs good).
PMMA-HIChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
PMMA-HRChoose it when strength drives the design, or when the part sees heat.
PMMA-HI vs PMMA-HR: 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
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
Same in both: Poisson's Ratio 0.38
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 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)
Max Service Temperature (short-term)
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 · Min Service Temperature -40°C-40 °F · Limiting Oxygen Index 18%
Electrical
Conductivity and insulation.
Dissipation Factor (1 MHz)
Surface Resistivity
Same in both: Electrical Resistivity 1×10¹³ Ω·m3.94×10²⁰ µΩ·in · Dielectric Strength 25 kV/mm635 V/mil · Dielectric Constant (1 MHz) 2.8 · Volume Resistivity 1×10¹⁵ Ω·cm · 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 Carbon (primary production)
Embodied Water
Typical Recycled Content
Same in both: Embodied Energy (primary production) 103 MJ/kg44,282 BTU/lb
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-HI | PMMA-HR |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | — | — |
| Best machined surface | — | — |
PMMA-HI vs PMMA-HR — frequently asked
Is PMMA-HR stronger than PMMA-HI?
Yes. PMMA-HR has a typical yield strength of 72 MPa (10.4 ksi) against 48 MPa (6.96 ksi) for PMMA-HI — about 50% more. Tensile strength is 74 MPa (10.7 ksi) vs 50 MPa (7.25 ksi).
Which is cheaper, PMMA-HI or PMMA-HR?
Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, PMMA-HI or PMMA-HR?
PMMA-HI. Its machinability rates very good (78/100) against good (68/100) for PMMA-HR; for welding the order is PMMA-HI first (good, 62/100) then PMMA-HR (good, 55/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in PMMA-HI and PMMA-HR 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.