Is PLA Strong?
Where the confusion comes from
PLA has high tensile strength in pure pull tests, which makes it look strong on paper. In real-world use, PLA fails in three ways that the tensile number does not capture: brittle under impact, creeps under sustained load, and softens at car-interior temperatures.
Real-world PLA failures
- Brittle: snaps under impact instead of bending
- Creep: a PLA hook holding a kettle sags over weeks
- Heat softening: a PLA mount in a parked car fails in summer
- UV degradation: outdoor PLA goes brittle over months
When PLA is strong enough
- Indoor decorative pieces
- Miniatures and display models
- Prototypes that get binned
- Low-load static parts (cable clips, photo frames)
When to step up
- Functional parts: PETG or PCTG
- Heat or impact: ABS, ASA or PC
- Living hinges, snap-fits: nylon
- Maximum stiffness: PA-CF
Browse
PETG, Nylon, All PLA. Related: Best filament for functional parts.