LDPE vs UHMW-PE
Polymer · grade comparison
LDPE and UHMW-PE are both polymer grades. UHMW-PE is the stronger of the two: yield strength 21 MPa (3.05 ksi) against 10 MPa (1.45 ksi) for LDPE, about 110% more; tensile strength follows at 40 MPa (5.8 ksi) vs 11 MPa (1.6 ksi). In exchange, LDPE is the more ductile: elongation 450% versus 350% for UHMW-PE, and UHMW-PE is harder (64 Shore D vs 47 Shore D). UHMW-PE is stiffer (0.72 GPa vs 0.22 GPa) and UHMW-PE runs hotter in service (80°C vs 70°C continuous). On the shop floor, UHMW-PE machines more easily (very good vs fair), LDPE welds better (excellent vs poor), and LDPE sits in a lower cost tier (budget, $) than UHMW-PE (standard, $$).
LDPEChoose it when the part is bent, formed or impact-loaded, or when it will be welded.
UHMW-PEChoose it when strength drives the design, or when the part sees heat.
LDPE vs UHMW-PE: 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 A
Hardness, Shore D
Tear Strength
Hardness, Rockwell R
Physical
Density and transition temperatures.
Density
Melting Temperature (Tm)
Glass Transition (Tg)
Water Absorption (Saturation)
Light Transmission
Same in both: Water Absorption (24 h) 0.01% · Refractive Index 1.51
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)
Limiting Oxygen Index
Max Service Temperature (short-term)
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Strength
Dielectric Constant (1 MHz)
Volume Resistivity
Surface Resistivity
Same in both: Dissipation Factor (1 MHz) 3×10⁻⁴ · 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
Weldability
Formability (cold)
Polishability
Mold Shrinkage
Melt Flow Rate
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Same in both: Thermal Diffusivity 0.2 mm²/s · 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 | LDPE | UHMW-PE |
|---|---|---|
| CNC machining | — | Yes |
| Default condition | Unfilled | FDA |
| Relative cost | $ Budget | $$ Standard |
| 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.
LDPE vs UHMW-PE — frequently asked
Is UHMW-PE stronger than LDPE?
Yes. UHMW-PE has a typical yield strength of 21 MPa (3.05 ksi) against 10 MPa (1.45 ksi) for LDPE — about 110% more. Tensile strength is 40 MPa (5.8 ksi) vs 11 MPa (1.6 ksi).
Which is cheaper, LDPE or UHMW-PE?
LDPE is the lower-cost material: it sits in the budget tier ($) while UHMW-PE is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which is easier to machine, LDPE or UHMW-PE?
UHMW-PE. Its machinability rates very good (75/100) against fair (45/100) for LDPE; for welding the order is LDPE first (excellent, 95/100) then UHMW-PE (poor, 15/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in LDPE and UHMW-PE 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.