The short answer
HDPE is the low-cost, easy-to-process choice for molded and extruded products. UHMW has far longer molecular chains, giving outstanding wear resistance, impact strength and low friction, but it cannot be molded like normal plastics and is usually machined from sheet or rod.
HDPE and UHMW are both polyethylene, so they look and feel similar and resist the same chemicals. The difference is chain length, and it changes how the material wears, how tough it is and how it can be processed.
Side by side
| Property | HDPE | UHMW-PE |
|---|---|---|
| Molecular weight | ~50,000–300,000 (typical) | ~3 to 7.5 million or more |
| Density | ~0.94–0.97 g/cm³ | ~0.93–0.94 g/cm³ |
| Melt flow | Measurable; flows well | Essentially none |
| Processing | Injection, blow molding, extrusion, rotomolding | Compression molding, ram extrusion, then machining |
| Abrasion resistance | Good | Outstanding |
| Notched Izod impact | Moderate | Very high; often no break |
| Coefficient of friction | Low | Very low; self-lubricating |
| Stiffness | Higher | Lower |
| Max continuous use | ~80°C | ~80–90°C |
| Relative cost | Lower | Higher |
| Typical uses | Containers, pails, pipe, crates, cutting boards, film | Wear strips, chute liners, conveyor guides, bearings, bushings |
Typical values; grades vary. UHMW is defined in ASTM D4020 by its very high molecular weight.
Choose HDPE when
- The part will be injection molded, blow molded or extruded
- Cost per part matters most
- Wear is light or occasional
- Containers, pipe, crates, tanks, film
Choose UHMW when
- Parts slide, rub or see abrasive material
- Impact is severe, including in the cold
- Low friction without lubrication is needed
- Wear strips, liners, guides, bushings
The middle ground: HMW-HDPE
High molecular weight HDPE has longer chains than standard HDPE, so it is tougher and resists stress cracking better, yet it can still be extruded and blow molded. It is common in pressure pipe, large blow-molded containers and sheet. See HMW-HDPE.
See also HDPE vs. LDPE, PP vs. HDPE and wear and friction fillers.
Grades we source
We source injection, blow molding and extrusion grades of HDPE, HMW-HDPE and UHMW-PE resin, with a COA on every lot, tested to ASTM or ISO methods. See HDPE injection grades and UHMW-PE.
Common questions
What is the difference between HDPE and UHMW?
Both are polyethylene. UHMW (ultra-high molecular weight polyethylene) has molecular chains roughly ten times longer or more, which gives it far better wear and impact resistance and lower friction. The trade-off is that it cannot be injection molded or extruded like normal plastics.
Is UHMW stronger than HDPE?
UHMW is much tougher and far more wear resistant. HDPE is stiffer and has somewhat higher tensile strength at yield. For sliding wear, abrasion and impact, UHMW wins clearly.
Can UHMW be injection molded?
Not in standard grades. Its melt is too viscous to flow, so UHMW is compression molded or ram extruded into sheet, rod and profiles, and parts are machined from those shapes.
Is UHMW more expensive than HDPE?
Yes, both per pound and in part cost, because UHMW parts are usually machined from stock shapes rather than molded.
What is HMW-HDPE?
High molecular weight HDPE sits between the two. It has longer chains than standard HDPE for better toughness and stress-crack resistance, but it can still be extruded and blow molded.
Which is better for wear strips and chute liners?
UHMW. Its abrasion resistance and low friction make it the standard for wear strips, conveyor guides, chute and hopper liners and bearing pads.
Tell us the grade you need
A polymer chemist reviews every request, then matches your grade or finds a qualified equivalent and prices it.
What to send for an accurate quote
- The grade name, from any supplier, or a data sheet
- Color (natural, black or a custom match)
- Fill type and percentage, if any
- Melt flow, if you know it
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