High Density Polyethylene (HDPE)
HDPE is a thermoplastic, further classified as a polyethylene plastic.
The properties of HDPE include three common variations. This page shows summary ranges across all of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare HDPE to: polyethylene plastics (top), all thermoplastics (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Elongation at Break
2.5 to 100 %
Flexural Modulus
4.0 to 7.5 GPa 0.58 to 1.1 x 106 psi
Impact Strength: Notched Izod
50 to 260 J/m 0.94 to 4.8 ft-lb/in
Tensile Strength: Ultimate (UTS)
24 to 80 MPa 3.4 to 12 x 103 psi
Thermal Properties
Maximum Temperature: Mechanical
90 °C 190 °F
Specific Heat Capacity
1330 to 2400 J/kg-K 0.32 to 0.57 BTU/lb-°F
Otherwise Unclassified Properties
Density
1.0 to 1.3 g/cm3 59 to 79 lb/ft3
Water Absorption At Saturation
0.1 to 0.3 %
Common Calculations
Strength to Weight: Axial
6.9 to 17 points
Strength to Weight: Bending
19 to 32 points
Followup Questions
Further Reading
ASTM D883: Standard Terminology Relating to Plastics
Reinforced Plastics Durability, Geoffrey Pritchard (editor), 1999
SPI Plastics Engineering Handbook of the Society of the Plastics Industry, Inc., 5th ed., Michael L. Berins (editor), 2000
Modern Plastics Handbook, Charles A. Harper (editor), 1999
Plastics Materials, 7th ed., J. A. Brydson, 1999