PAR GF20 vs PAR GF30
Polymer · PAR grade comparison
PAR GF20 and PAR GF30 are two grades of the same polymer grade, PAR: GF20 (20 % glass-fiber reinforced) versus GF30 (30 % glass-fiber reinforced). The chemistry is identical, so every difference below comes from the condition. PAR GF30 is the stronger of the two: tensile strength 120 MPa (17.4 ksi) against 100 MPa (14.5 ksi) for PAR GF20, about 20% more. In exchange, PAR GF20 is the more ductile: elongation 4% versus 2.5% for PAR GF30. PAR GF20 is lighter (1.35 g/cm³ vs 1.45 g/cm³ for PAR GF30) and PAR GF30 is stiffer (8.5 GPa vs 5.8 GPa).
PAR GF20Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
PAR GF30Choose it when strength drives the design.
PAR GF20 vs PAR GF30: 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
Tensile Strength (Ultimate)
Elongation at Break
Flexural Strength
Flexural Modulus
Izod Impact, Notched
Same in both: Shear Modulus 0.75 GPa0.11 Msi · Bulk Modulus 4 GPa0.51 Msi · Poisson's Ratio 0.4 · Yield Strength (0.2% offset) 68 MPa9.9 ksi · Compressive Strength 85 MPa12.3 ksi · Compressive Modulus 2.2 GPa0.32 Msi · Shear Strength 58 MPa8.4 ksi · Hardness, Shore D 85 Shore D · Hardness, Rockwell M 88 HRM · Hardness, Rockwell R 125 HRR
Physical
Density and transition temperatures.
Density
Same in both: Glass Transition (Tg) 190°C374 °F · Water Absorption (24 h) 0.26% · Water Absorption (Saturation) 0.8% · Refractive Index 1.61 · Light Transmission 0%
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. @ 1.8 MPa
Same in both: Thermal Conductivity 0.18 W/m·K0.1 BTU/hr·ft·°F · Specific Heat Capacity 1,200 J/kg·K0.29 BTU/lb·°F · Min Service Temperature -50°C-58 °F · Heat Deflection Temp. @ 0.45 MPa 185°C365 °F · Vicat Softening Point (B50) 187°C369 °F · Limiting Oxygen Index 34% · Max Service Temperature (short-term) 180°C356 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Dielectric Strength 20 kV/mm508 V/mil · Dielectric Constant (1 MHz) 3 · Dissipation Factor (1 MHz) 0.012 · Volume Resistivity 1×10¹⁶ Ω·cm · Surface Resistivity 1×10¹⁵ Ω · Comparative Tracking Index (CTI) 200 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Corrosion Resistance 85 / 100 · UV / Weathering Resistance 90 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Mold Shrinkage
Same in both: Weldability 60 / 100 · Formability (cold) 55 / 100 · Polishability 75 / 100 · Processing Melt Temperature (typ.) 340°C644 °F · Mold Temperature (typ.) 130°C266 °F
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 145 MJ/kg62,339 BTU/lb · Embodied Carbon (primary production) 7.5 kg CO₂/kg · Embodied Water 350 L/kg41.9 gal/lb · Typical Recycled Content 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.
PAR GF20 vs PAR GF30 — frequently asked
Is PAR GF30 stronger than PAR GF20?
Yes. PAR GF30 has a typical tensile strength of 120 MPa (17.4 ksi) against 100 MPa (14.5 ksi) for PAR GF20 — about 20% more.
Which grade does FabDigit quote by default, GF20 or GF30?
Specify the condition in the material field or the drawing note; FabDigit prices the quote for the state you call out.
Which is easier to machine, PAR GF20 or PAR GF30?
PAR GF20, by a small margin. Both rate fair for machinability — 48/100 against 42/100 for PAR GF30.
Ready to make it?
Upload a CAD file and FabDigit prices the part in PAR GF20 and PAR GF30 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.