ABS vs ASA: what's the difference?

On these two PolyLite sheets the heat difference is a few degrees, and the beds are not the same. UV hours are not in the rows. ABS printing ASA printing fumes PETG versus ABS and ASA PETG outdoors.

Same brand, both loads

PolyLite ABS lists 230–260 °C (446–500 °F), a bed of 90–110 °C (194–230 °F), and drying at 70 °C (158 °F) for 6 h. Heat-deflection temperature, checked 21 October 2026, is 100 °C (212 °F) at 0.45 MPa and 98 °C (208 °F) at 1.8 MPa, ISO 75. Vicat is 104 °C (219 °F), ISO 306, load blank. Glass transition is 101 °C (214 °F). Enclosure required is blank. PolyLite ASA lists the same nozzle, a bed of 75–95 °C (167–203 °F), and drying at 70 °C (158 °F) for 7 h. Heat-deflection is 103 °C (217 °F) at 0.45 MPa and 100 °C (212 °F) at 1.8 MPa. Vicat is 105 °C (221 °F), load blank. Glass transition is 98 °C (208 °F). Enclosure required is true.

Glass transition runs the other way from heat deflection: ABS is 101 °C (214 °F) and ASA is 98 °C (208 °F). Tensile strength, impact, and UV hours are absent, so they are not compared. Bambu Lab ABS lists 230–260 °C (446–500 °F), a bed of 90–110 °C (194–230 °F), and drying at 80 °C (176 °F) for 8 h, with no heat-deflection row in the dataset. The order is ABS, ASA, then a second ABS print setting. It is not a UV ranking and not a price ranking.

What the community says

a Reddit thread in r/BambuLab: One says ASA resists a bit better and that both print like PLA, and names Polymaker ASA for colors.

a Reddit thread in r/BambuLab: UV, odor, and "prints like PLA" stay comments.

a Reddit thread in r/3Dprinting calls both fairly toxic and ABS more so, and wants ventilation or a filter.

Questions