- Lab test
- By Sample Author
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Sample content: placeholder text for layout review. Names, numbers and claims are not real.
Which common filament is strongest when printed flat? We printed ISO 527-2 type 1A dog-bone specimens in PLA, PETG and ABS with identical settings and pulled five of each to failure. This article reports what we measured, how, and where the numbers stop being useful.
Key findings
- PLA had the highest mean tensile strength: 51.6 MPa (95% CI 49.9–53.2 MPa, n = 5), printed flat (XY), 100% infill, tested September 2026.
- PETG reached 47.9 MPa (95% CI 46.3–49.5) but stretched about twice as far before breaking (8.1% vs 3.8% for PLA).
- ABS was the weakest in tension at 40.0 MPa (95% CI 38.6–41.3); PLA was about 29% stronger.
- Results apply to flat-printed specimens only; vertical (Z) prints are typically much weaker and were not tested here.
Methodology
Materials and printing
One 1 kg spool per material from a single retail batch (brands withheld in this sample). All specimens were printed on the same printer with a 0.4 mm nozzle, 0.2 mm layers, 100% rectilinear infill at ±45°, two perimeters, flat on the bed (XY orientation). Nozzle temperature followed each manufacturer’s midpoint. Filament was dried for 6 hours before printing.
Test setup
Specimens were conditioned for 48 hours at 23 °C and 50% relative humidity, measured with a calibrated micrometer, and tested on a universal testing machine at 5 mm/min following ISO 527-1/-2. Tensile strength is the maximum stress; elongation is the nominal strain at break.
Statistics
For each material we report the mean, sample standard deviation (SD) and a 95% confidence interval for the mean (Student’s t, df = 4). All values are calculated by script from the raw CSV linked below; no number in this article is typed by hand.
Results
| Material | n | Tensile strength, mean (MPa) | SD (MPa) | 95% CI (MPa) | Elongation at break, mean (%) | SD (%) |
|---|---|---|---|---|---|---|
| PLA | 5 | 51.6 | 1.34 | 49.9–53.2 | 3.8 | 0.24 |
| PETG | 5 | 47.9 | 1.31 | 46.3–49.5 | 8.1 | 0.63 |
| ABS | 5 | 40.0 | 1.08 | 38.6–41.3 | 6.1 | 0.45 |
The confidence intervals of PLA and PETG barely overlap, so the difference between them is small but likely real for this setup. ABS is clearly separated from both.
What this means for your prints
For stiff, flat-loaded parts at room temperature, PLA is the strongest of the three. Where parts must bend or absorb a knock without snapping, PETG’s higher elongation usually matters more than its slightly lower strength. ABS earns its place through heat resistance, which this test does not measure.
Limitations
- Five specimens per material from one spool each: brand-to-brand and batch-to-batch variation is not covered.
- Only XY orientation; layer adhesion (Z direction) is the usual failure mode in real parts.
- Room temperature only; PLA softens near 55–60 °C, so the ranking changes in warm environments.
- One printer and one set of settings; other settings can shift results by 10–20%.
Data and reproducibility
- Download the raw data (CSV)
- Measurement technique: Uniaxial tensile test, ISO 527-1/-2, 5 mm/min
- Measured variables: Tensile strength (MPa), Elongation at break (%)
- License: CC BY 4.0 — Data licensed under CC BY 4.0: free to reuse with attribution.
References
- ISO 527-1:2019 Plastics — Determination of tensile properties — Part 1: General principles https://www.iso.org/standard/75824.html
- ISO 527-2:2012 Plastics — Determination of tensile properties — Part 2: Test conditions for moulding and extrusion plastics https://www.iso.org/standard/56046.html
How to cite
Sample Author (2026). PLA vs PETG vs ABS: tensile strength of 3D-printed specimens. Horizon Test Lab. https://horizontestlab.com/en/pla-petg-abs-tensile-strength-test/
Disclosures
- Analysis and writing assisted by AI; data and conclusions verified by the author.
- The author reports no conflicts of interest.
- Featured image: Photo: Majabojarska, CC BY 4.0, via Wikimedia Commons
Changelog
- : First version (sample)