General Purpose A40 vs General Purpose GF30
Polyurethane · General Purpose grade comparison
General Purpose A40 and General Purpose GF30 are two grades of the same polyurethane grade, General Purpose: A40 (shore A 40) versus GF30 (30% glass-fiber reinforced rigid PU / RIM). The chemistry is identical, so every difference below comes from the condition. General Purpose GF30 is the stronger of the two: tensile strength 80 MPa (11.6 ksi) against 18 MPa (2.61 ksi) for General Purpose A40, about 4.4 times as much. In exchange, General Purpose A40 is the more ductile: elongation 700% versus 4% for General Purpose GF30, and General Purpose GF30 is harder (82 Shore D vs 10 Shore D). General Purpose A40 is lighter (1.2 g/cm³ vs 1.38 g/cm³ for General Purpose GF30) and General Purpose GF30 is stiffer (5 GPa vs 0 GPa). On the shop floor, General Purpose GF30 machines more easily (good vs poor).
General Purpose A40Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
General Purpose GF30Choose it when strength drives the design, or when the part sees heat.
General Purpose A40 vs General Purpose GF30: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all polyurethane 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 polyurethane 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.
General Purpose A40General Purpose GF30
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Tensile Strength (Ultimate)
Elongation at Break
Compressive Strength
Shear Strength
Hardness, Shore A
Hardness, Shore D
Tear Strength
Compression Set (22 h, 70 °C)
Same in both: Poisson's Ratio 0.48
Physical
Density and transition temperatures.
Density
Same in both: Glass Transition (Tg) -35°C-31 °F · Water Absorption (24 h) 0.6% · Water Absorption (Saturation) 1.8%
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Limiting Oxygen Index
Same in both: Specific Heat Capacity 1,750 J/kg·K0.42 BTU/lb·°F · Min Service Temperature -40°C-40 °F · Max Service Temperature (short-term) 120°C248 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Resistivity 1×10¹⁰ Ω·m3.94×10¹⁷ µΩ·in · Dielectric Strength 22 kV/mm559 V/mil · Dielectric Constant (1 MHz) 5 · Dissipation Factor (1 MHz) 0.05 · Volume Resistivity 1×10¹² Ω·cm · Surface Resistivity 1×10¹³ Ω · Comparative Tracking Index (CTI) 600 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: UV / Weathering Resistance 35 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Formability (cold)
Mold Shrinkage
Same in both: Weldability 15 / 100 · Polishability 30 / 100 · Mold Temperature (typ.) 100°C212 °F
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 105 MJ/kg45,142 BTU/lb · Embodied Carbon (primary production) 5 kg CO₂/kg · Embodied Water 300 L/kg35.9 gal/lb · Typical Recycled Content 3%
Strength versus weight
Yield strength against density for every polyurethane grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
General Purpose A40 vs General Purpose GF30 — frequently asked
Is General Purpose GF30 stronger than General Purpose A40?
Yes. General Purpose GF30 has a typical tensile strength of 80 MPa (11.6 ksi) against 18 MPa (2.61 ksi) for General Purpose A40 — about 4.4 times as much.
Which grade does FabDigit quote by default, A40 or GF30?
GP-A80 is the default General Purpose condition in the FabDigit quote flow (neither A40 nor GF30). The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.
Which is easier to machine, General Purpose A40 or General Purpose GF30?
General Purpose GF30. Its machinability rates good (55/100) against poor (30/100) for General Purpose A40.
Ready to make it?
Upload a CAD file and FabDigit prices the part in General Purpose A40 and General Purpose 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.