HDPE properties
HDPE is high-density polyethylene, a tough, lightweight, chemically resistant thermoplastic. It is inexpensive, easy to weld and fabricate, and floats on water. It is used for tanks, piping, cutting boards, and outdoor parts.
Mechanical properties
| Property | Value |
|---|---|
| Tensile strength | 4,000 psi (28 MPa) |
| Flexural modulus | 200,000 psi (1.4 GPa) |
| Elongation at break | 500% |
| Hardness | Shore D 65 |
Physical properties
| Property | Value |
|---|---|
| Density | 0.035 lb/in³ (960 kg/m³) |
| Melting point | about 130 °C |
Thermal properties
| Property | Value |
|---|---|
| Max service temperature | about 80 °C continuous |
| Thermal expansion | 200 µm/m·°C |
| Thermal conductivity | 0.48 W/m·K |
Values are typical for the grade and condition shown. Actual properties vary with temper, heat treatment, and product form, so use these for comparison and preliminary design and confirm against material certificates for final work.
Compare with other materials
See the Material Properties Comparison, Yield Strength, and Density charts.
Typical uses
HDPE is used for tanks, jugs, piping, cutting boards, marine parts, and outdoor furniture. Its chemical resistance, low cost, light weight, and weldability make it a workhorse for fluid storage and fabricated plastic parts, and it is fully recyclable.
How it compares
HDPE is cheaper and less abrasion resistant than UHMW but easier to fabricate and weld, and it is far more chemically resistant than ABS or nylon. It is soft and low strength, so it suits containers and liners rather than load-bearing structural parts.
FAQ
Is HDPE food safe?
Yes, HDPE is widely used for food containers and cutting boards. It is inert, easy to clean, and approved for food contact.
Can HDPE be welded?
Yes. It is readily plastic-welded, which is how HDPE tanks and pipe are fabricated and joined, since it cannot be solvent cemented.
Does HDPE float?
Yes. Its density is below that of water, around 0.96, so HDPE parts float, which suits marine and dock applications.