What wear resistance means
Wear resistance is a material’s ability to resist gradual loss of surface material caused by rubbing, sliding, rolling or abrasive particles. It is not a single property you can read off a datasheet like density. Instead it is judged through tests and through practical experience with a given application.
Wear is different from impact. A plastic that survives a hard blow may still wear quickly when it slides against metal. For the impact side, see impact strength of plastics compared.
Wear is a system property
The same plastic can wear well in one setup and badly in another. The result depends on:
- The mating surface, including its hardness and roughness.
- Load and sliding speed, which together drive frictional heating.
- Temperature, since many plastics soften as they warm up.
- Lubrication, whether built in, applied or absent.
- Contamination such as dust or grit that acts as an abrasive.
Because of this, treat any “best wear plastic” list as a starting point and test in your own conditions.
Plastics commonly chosen for wear
These materials are widely used for sliding and wear parts. Descriptions are general and vary by grade.
- UHMWPE (ultra-high-molecular-weight polyethylene). Known for abrasion resistance and low friction, used for liners, guides and chain parts. It is soft and has a relatively low temperature limit.
- Acetal (POM, Delrin is a common brand). Stiff, low friction and dimensionally stable, popular for gears and bushings.
- Nylon (PA). Tough with good wear behavior, but it absorbs moisture, which changes its size and properties.
- PET and PBT. Strong, dimensionally stable plastics that are frequently described as having good wear properties.
- PEEK. A high-performance plastic with good wear and chemical resistance across a wide temperature range, at a much higher cost.
- Polyimides (such as Vespel). Used for extreme temperatures, with excellent friction and wear characteristics, and very expensive.
- PTFE. Very low friction, but unfilled PTFE can wear and creep readily, so filled grades are common for bearings.
- Polyurethane and TPU. Rubber-like materials that resist abrasion well, used for wheels, seals and protective parts.
Curbell Plastics groups several of these (acrylic, PEEK, PET, PBT, PETG and others) under strong and stiff plastics, and stresses that the right choice depends on load, temperature, wear, impact and chemical exposure together.
Fillers and additives
Manufacturers often modify base plastics to improve wear:
- Solid lubricants such as PTFE or graphite lower friction.
- Glass or carbon fiber raises stiffness and can improve wear resistance, though fibers can be abrasive to the mating surface.
- Internal lubricants in some nylon and acetal grades reduce sticking and noise.
If you 3D print with carbon-fiber or glass-filled filaments, be aware that they can wear down soft brass nozzles, so a hardened nozzle is usually recommended.
Which plastic types are durable?
Durability depends on what you need it to withstand. Engineering plastics such as nylon, acetal, polycarbonate and PEEK are generally chosen for demanding mechanical jobs, while commodity plastics such as polyethylene and polypropylene are chosen for low cost and chemical resistance. No plastic is best at everything.
Downsides of polypropylene
Polypropylene (PP) is inexpensive, light and chemically resistant, but it has limitations:
- It is relatively soft and not ideal for high-load wear parts.
- It can become brittle in cold conditions and degrades with prolonged UV exposure unless stabilized.
- It is hard to glue or paint without surface treatment.
- It shrinks and warps considerably, which makes it challenging to 3D print.
The 7 main types of plastic
The “7 types” people often ask about come from the resin identification codes on packaging:
- PET (polyethylene terephthalate)
- HDPE (high-density polyethylene)
- PVC (polyvinyl chloride)
- LDPE (low-density polyethylene)
- PP (polypropylene)
- PS (polystyrene)
- Other, which covers everything else, including polycarbonate, nylon and acrylic
These codes are for recycling, not wear performance, so they are a poor guide for engineering selection.
Wear resistance for 3D printed parts
Printed parts usually wear faster than molded or machined parts because layer lines are rough and layers can separate. If you print sliding parts:
- Consider nylon or TPU for parts that rub or flex. Our PETG vs nylon comparison covers the wear and drying trade-offs.
- Print with more walls and a denser outer shell, since wear affects the surface. The infill density guide explains why walls often matter more than infill.
- Orient the part so that sliding does not peel layers apart.
- Use different materials for each side of a sliding pair where possible.
- Test with a real prototype under real load before trusting it.
How to choose
Start from the application: how fast it slides, how heavy the load is, how warm it gets, and what it rubs against. Pick a likely material, then check the manufacturer’s data for that grade. Combine this with impact strength information if shock loads are also expected.