HDPE BM vs HDPE GF30
Polymer · HDPE grade comparison
HDPE BM and HDPE GF30 are two grades of the same polymer grade, HDPE: BM (blow moulding grade) versus GF30 (30% glass fiber reinforced HDPE). The chemistry is identical, so every difference below comes from the condition. HDPE GF30 is the stronger of the two: yield strength 26 MPa (3.77 ksi) against 24 MPa (3.48 ksi) for HDPE BM, about 8% more; tensile strength follows at 55 MPa (7.98 ksi) vs 26 MPa (3.77 ksi). In exchange, HDPE BM is the more ductile: elongation 700% versus 3% for HDPE GF30, and HDPE GF30 is harder (72 Shore D vs 63 Shore D). HDPE BM is lighter (0.95 g/cm³ vs 1.18 g/cm³ for HDPE GF30) and HDPE GF30 is stiffer (5.5 GPa vs 1 GPa). On the shop floor, HDPE BM welds better (excellent vs fair).
HDPE BMChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
HDPE GF30Choose it when strength drives the design.
HDPE BM vs HDPE 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)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Flexural Strength
Flexural Modulus
Shear Strength
Fracture Toughness (K_IC)
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell R
Same in both: Shear Modulus 0.4 GPa0.06 Msi · Bulk Modulus 3 GPa0.44 Msi · Poisson's Ratio 0.44 · Compressive Modulus 0.9 GPa0.13 Msi
Physical
Density and transition temperatures.
Density
Same in both: Melting Temperature (Tm) 132°C270 °F · Glass Transition (Tg) -110°C-166 °F · Water Absorption (24 h) 0.01% · Water Absorption (Saturation) 0.05% · Refractive Index 1.54
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Same in both: Specific Heat Capacity 1,900 J/kg·K0.45 BTU/lb·°F · Max Service Temperature (continuous) 80°C176 °F · Min Service Temperature -80°C-112 °F · Limiting Oxygen Index 18% · Max Service Temperature (short-term) 110°C230 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Dielectric Strength 24 kV/mm610 V/mil · Dielectric Constant (1 MHz) 2.35 · Dissipation Factor (1 MHz) 3×10⁻⁴ · Volume Resistivity 1×10¹⁶ Ω·cm · Surface Resistivity 1×10¹⁵ Ω · Comparative Tracking Index (CTI) 600 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Corrosion Resistance 90 / 100 · UV / Weathering Resistance 25 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Mold Shrinkage
Melt Flow Rate
Processing Melt Temperature (typ.)
Same in both: Polishability 30 / 100 · Mold Temperature (typ.) 40°C104 °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 90 L/kg10.8 gal/lb · Typical Recycled Content 10%
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.
HDPE BM vs HDPE GF30 — frequently asked
Is HDPE GF30 stronger than HDPE BM?
Yes. HDPE GF30 has a typical yield strength of 26 MPa (3.77 ksi) against 24 MPa (3.48 ksi) for HDPE BM — about 8% more. Tensile strength is 55 MPa (7.98 ksi) vs 26 MPa (3.77 ksi).
Which grade does FabDigit quote by default, BM 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, HDPE BM or HDPE GF30?
HDPE BM. Its machinability rates good (58/100) against fair (50/100) for HDPE GF30; for welding the order is HDPE BM first (excellent, 92/100) then HDPE GF30 (fair, 45/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in HDPE BM and HDPE 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.