HDPE vs LDPE
Polymer · grade comparison
HDPE and LDPE are both polymer grades, both corrosion resistant plastic. HDPE is the stronger of the two: yield strength 26 MPa (3.77 ksi) against 10 MPa (1.45 ksi) for LDPE, about 160% more; tensile strength follows at 28 MPa (4.06 ksi) vs 11 MPa (1.6 ksi). HDPE is the more ductile: elongation 600% versus 450% for LDPE, and HDPE is harder (65 Shore D vs 47 Shore D). LDPE is lighter (0.92 g/cm³ vs 0.96 g/cm³ for HDPE) and HDPE is stiffer (1.1 GPa vs 0.22 GPa). On the shop floor, HDPE machines more easily (very good vs fair).
HDPEChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
LDPEChoose it when weight is the constraint.
HDPE vs LDPE: 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
Poisson's Ratio
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 R
Hardness, Shore A
Tear Strength
Physical
Density and transition temperatures.
Density
Melting Temperature (Tm)
Water Absorption (Saturation)
Refractive Index
Light Transmission
Same in both: Glass Transition (Tg) -110°C-166 °F · Water Absorption (24 h) 0.01%
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Min Service Temperature
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Max Service Temperature (short-term)
Same in both: Limiting Oxygen Index 18%
Electrical
Conductivity and insulation.
Dielectric Strength
Dielectric Constant (1 MHz)
Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · 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).
Corrosion Resistance
UV / Weathering Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Formability (cold)
Mold Shrinkage
Melt Flow Rate
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Same in both: Weldability 95 / 100 · Polishability 30 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 10%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Same in both: 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 | HDPE | LDPE |
|---|---|---|
| CNC machining | Yes | — |
| Default condition | FDA Compliant | Unfilled |
| Relative cost | $ Budget | $ Budget |
| Min. machined wall | 0.5 mm | — |
| Best machined surface | Ra 0.8 µm | — |
Both are offered for Sheet metal and Injection molding. Both take the same 6 finishes: Chrome Plating (Plastic), EMI Shielding Coating, Painting, Soft Touch Coating, Spray Painting, UV Coating.
HDPE vs LDPE — frequently asked
Is HDPE stronger than LDPE?
Yes. HDPE has a typical yield strength of 26 MPa (3.77 ksi) against 10 MPa (1.45 ksi) for LDPE — about 160% more. Tensile strength is 28 MPa (4.06 ksi) vs 11 MPa (1.6 ksi).
Which is cheaper, HDPE or LDPE?
Both sit in the same relative cost tier ($, budget); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, HDPE or LDPE?
HDPE. Its machinability rates very good (75/100) against fair (45/100) for LDPE.
Ready to make it?
Upload a CAD file and FabDigit prices the part in HDPE and LDPE 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.