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PP-H GF20 vs PP-H GF40

Polymer · PP-H grade comparison

PP-H GF20 and PP-H GF40 are two grades of the same polymer grade, PP-H: GF20 (20 % coupled glass-fiber reinforced PP homopolymer) versus GF40 (40 % coupled glass-fiber reinforced PP homopolymer). The chemistry is identical, so every difference below comes from the condition. PP-H GF40 is the stronger of the two: tensile strength 105 MPa (15.2 ksi) against 75 MPa (10.9 ksi) for PP-H GF20, about 40% more. In exchange, PP-H GF20 is the more ductile: elongation 3% versus 2.5% for PP-H GF40. PP-H GF20 is lighter (1.04 g/cm³ vs 1.22 g/cm³ for PP-H GF40) and PP-H GF40 is stiffer (8.5 GPa vs 5 GPa). On the shop floor, PP-H GF20 machines more easily (good vs fair) and PP-H GF20 welds better (very good vs good).

PP-H GF20Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.

PP-H GF40Choose it when strength drives the design.

PP-H GF20 vs PP-H GF40: properties

PP-H GF20PP-H GF40

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

5 GPa0.73 Msi
8.5 GPa1.2 Msi

Tensile Strength (Ultimate)

75 MPa10.9 ksi
105 MPa15.2 ksi

Elongation at Break

3%
2.5%

Compressive Strength

70 MPa10.2 ksi
95 MPa13.8 ksi

Flexural Strength

110 MPa16 ksi
150 MPa21.8 ksi

Flexural Modulus

4.5 GPa0.65 Msi
8 GPa1.2 Msi

Fracture Toughness (K_IC)

4 MPa·√m3.6 ksi·√in
5 MPa·√m4.6 ksi·√in

Izod Impact, Notched

80 J/m1.5 ft·lbf/in
110 J/m2.1 ft·lbf/in

Hardness, Rockwell M

78 HRM
85 HRM

Hardness, Rockwell R

105 HRR
110 HRR

Same in both: Shear Modulus 0.5 GPa0.07 Msi · Bulk Modulus 4 GPa0.51 Msi · Poisson's Ratio 0.42 · Yield Strength (0.2% offset) 34 MPa4.9 ksi · Compressive Modulus 1.5 GPa0.22 Msi · Shear Strength 25 MPa3.6 ksi · Hardness, Shore D 72 Shore D

Physical

Density and transition temperatures.

Density

1.04 g/cm³0.04 lb/in³
1.22 g/cm³0.04 lb/in³

Same in both: Melting Temperature (Tm) 165°C329 °F · Glass Transition (Tg) -10°C14 °F · Water Absorption (24 h) 0.01% · Water Absorption (Saturation) 0.03% · Refractive Index 1.49

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

0.28 W/m·K0.16 BTU/hr·ft·°F
0.35 W/m·K0.2 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

40 µm/m·K22.2 µin/in·°F
25 µm/m·K13.9 µin/in·°F

Max Service Temperature (continuous)

120°C248 °F
130°C266 °F

Heat Deflection Temp. @ 0.45 MPa

155°C311 °F
160°C320 °F

Heat Deflection Temp. @ 1.8 MPa

135°C275 °F
155°C311 °F

Vicat Softening Point (B50)

155°C311 °F
160°C320 °F

Limiting Oxygen Index

19%
18%

Same in both: Specific Heat Capacity 1,900 J/kg·K0.45 BTU/lb·°F · Min Service Temperature -10°C14 °F · Max Service Temperature (short-term) 130°C266 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Resistivity 1×10¹⁵ Ω·m3.94×10²² µΩ·in · Dielectric Strength 28 kV/mm711 V/mil · Dielectric Constant (1 MHz) 2.25 · Dissipation Factor (1 MHz) 3×10⁻⁴ · Volume Resistivity 1×10¹⁷ Ω·cm · Surface Resistivity 1×10¹⁵ Ω · Comparative Tracking Index (CTI) 600 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

85 / 100
82 / 100

Same in both: UV / Weathering Resistance 20 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

55 / 100
45 / 100

Weldability

70 / 100
60 / 100

Formability (cold)

25 / 100
15 / 100

Mold Shrinkage

0.5%
0.35%

Melt Flow Rate

5 g/10 min
4 g/10 min

Same in both: Polishability 30 / 100 · Processing Melt Temperature (typ.) 230°C446 °F · Mold Temperature (typ.) 35°C95 °F

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 100 L/kg12 gal/lb · Typical Recycled Content 3%

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.

0.1110100123Density (g/cm³)Yield strength (MPa) — log scalePP-H

PP-H GF20 vs PP-H GF40 — frequently asked

Is PP-H GF40 stronger than PP-H GF20?

Yes. PP-H GF40 has a typical tensile strength of 105 MPa (15.2 ksi) against 75 MPa (10.9 ksi) for PP-H GF20 — about 40% more.

Which grade does FabDigit quote by default, GF20 or GF40?

UNF is the default PP-H condition in the FabDigit quote flow (neither GF20 nor GF40). 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, PP-H GF20 or PP-H GF40?

PP-H GF20. Its machinability rates good (55/100) against fair (45/100) for PP-H GF40; for welding the order is PP-H GF20 first (very good, 70/100) then PP-H GF40 (good, 60/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in PP-H GF20 and PP-H GF40 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.