Compare ASA vs PETG for Your 3D Printing Project

Choosing between ASA and PETG depends on how the part will be used and what performance you expect. Both are widely used thermoplastics in FDM 3D printing. At the same time, they are not interchangeable. 

Upside Parts - ASA vs PETG

In this post, we compare ASA vs PETG using Bambu Lab data and provide clear guidance for selecting the right material for practical projects.

ASA vs PETG Compared with Real Data

Bambu ASA is formulated for environmental durability, including prolonged outdoor exposure. The published documentation describes strong resistance to UV, weather and heat (as per Bambu ASA TDS, PDF available at ASA | Bambu Lab US Store).

Bambu PETG HF focuses on ease of printing, layer adhesion, and functional toughness. It handles moisture well, but its long term behavior under sunlight is less robust than ASA (as per Bambu PETG HF TDS, PDF available at PETG HF | Bambu Lab US Store).

Mechanical Properties of ASA vs PETG

Here is a side-by-side comparison of mechanical performance based on Bambu’s TDS results, tested under consistent conditions:

Property	Bambu ASA	Bambu PETG HF
Tensile Strength (X-Y)	37 ± 3 MPa	34 ± 4 MPa
Young’s Modulus (X-Y)	2120 ± 260 MPa	1540 ± 130 MPa
Bending Strength (X-Y)	65 ± 5 MPa	64 ± 3 MPa
Impact Strength (notched X-Y)	19.6 ± 1.8 kJ/m²	6.2 ± 1.8 kJ/m²
Elongation at Break (X-Y)	9.2 ± 1.4%	8.6 ± 1.2%
Heat Deflection Temperature	92 °C (198 °F)	62 °C (144 °F)

These differences help define when PETG vs ASA makes sense.

Based on these results, ASA shows clearly higher stiffness and heat stability. It also absorbs impact energy more effectively, which can matter for parts exposed to mechanical stress. PETG HF remains functional and strong, but the noticeably lower heat deflection temperature means it is not well-suited for environments where temperatures may rise. The tensile strength values show both materials are viable for structural parts, although ASA performs slightly better. PETG HF stretches a bit more before breaking, but the difference is not large.

What Outdoor and Environmental Performance Means in Practice for PETG vs ASA

ASA is a better choice for parts exposed to sunlight. The ASA TDS notes the material can maintain structural and color stability outdoors. The PETG HF technical sheet notes moisture resistance.

If you want more depth on PETG and outdoor behavior, we prepared a detailed review you may read in our post on PETG for outdoor use.

Printability Differences that Matter

From a professional 3D printing service standpoint, ASA demands more controlled printing conditions. ASA benefits from an enclosed printer and higher bed temperature. Larger ASA parts can require brims to reduce curling.

PETG HF prints with lower bed temperature, bonds well between layers, and produces clean surfaces with less adjustment. This makes PETG advantageous for projects where print simplicity influences time and effectiveness.

Both materials can produce strong functional parts, but the manufacturing process is smoother with PETG.

Use Case Recommendations

The choice between PETG vs ASA depends on exposure, load, geometry, and expected life of the part.

Use case	Better choice
Outdoor parts exposed to sun	ASA
Indoor functional housings	PETG
Parts exposed to heat such as vehicle interiors	ASA
Moisture resistant parts not facing long sun exposure	PETG
Aesthetic visible parts that need smooth finish	PETG
Structural parts needing dimensional stability	ASA

If you are deciding on the best material option for an FDM printing application, you may also learn more on our blog about how to choose between ASA vs ABS for your project.

Dimensional and Aesthetic Considerations

ASA maintains shape over time when exposed to heat cycles. PETG may soften in hotter environments but stays dimensionally stable indoors.

PETG offers excellent visual quality. ASA produces strong parts, however the surface may require post processing for finishing.

Practical Considerations

When clients request a material decision, we look at the environment where the part will be used, the expected load, the need for dimensional tolerance, and the required turnaround on printing. PETG can reduce production time for short run or prototype work. ASA provides longevity where the environment stresses the part.

There is no universal winner in ASA vs PETG. ASA offers stronger UV and heat resistance and serves best outdoors. PETG offers strong durability, ease of printing, and smooth surface quality for parts.

We offer FDM printing with both materials. We provide 3D printing Boston services and ship functional parts nationwide. If you are uncertain which filament suits your design, our service team is glad to evaluate the application and perform test prints if needed.