Delrin and UHMW are both popular machinable plastics, but they behave very differently. Delrin is rigid and precise; UHMW is tough, slippery, and forgiving.
| Property | undefined | undefined |
|---|---|---|
| Stiffness (modulus) | High, 3.1 GPa | Low, 0.7 GPa |
| Strength | Higher | Lower |
| Wear / abrasion | Good | Excellent |
| Impact resistance | Good | Excellent |
| Friction | Low | Very low |
| Dimensional stability | Excellent | Fair, can creep |
| Density | 1.41 g/cc | 0.93 g/cc |
| Typical use | Precision gears, bushings | Wear strips, liners, chutes |
Which should you choose
Choose Delrin for rigid, dimensionally stable parts that need tight tolerances, such as gears, cams, and precision bushings.
Choose UHMW for abrasion and impact surfaces where toughness and a low-friction face matter more than stiffness, such as wear strips and chute liners.
Precision versus toughness. Delrin holds tight tolerances and stays rigid. UHMW shrugs off impact and abrasion but flexes and creeps, so it is not for precision parts.
FAQ
Which one machines more easily? Delrin (acetal) generally machines more cleanly to tighter tolerances, while UHMW is softer and gummier, making it better suited to wear strips and liners than precision machined parts.
Compare data sheets: Delrin (Acetal) and UHMW.