“What should this be made from?” starts with the part’s job. Nylon, PETG and ASA each describe material families, not a single specification. Grade, additives, print process and the environment all belong in the comparison.
The earlier guide’s generalized strength, temperature and price table has been removed. It should not be used as evidence that a particular printed part meets a requirement.
Start with the actual conditions
Write down the environment, loads and interfaces before choosing a material. Include how long the part is exposed, whether loads repeat or remain constant, and what happens if it deforms or fails.
For chemicals, identify the substance and concentration rather than saying only “chemical resistant.” For temperature, distinguish a brief exposure from sustained use. Include outdoor exposure, humidity, cleaning and assembly requirements where relevant.
Nylon: ask about grade and moisture
Nylon may be considered for parts needing mechanical or wear-related properties, but the particular grade matters. Ask how moisture conditioning affects the dimensions and properties used in the comparison, and what drying or processing requirements the supplier follows. Prusa’s nylon guide describes the material’s printing considerations.
Reinforced nylon introduces another set of choices. It should be compared using the actual datasheets and process, rather than treated as an automatic upgrade. See the reinforced nylon guide.
PETG: check the limits of the intended use
PETG may be a candidate for a practical prototype or component, but suitability for heat, sustained loads or a particular chemical needs evidence for the selected grade and process. A convenient printing material is not automatically the best final material. Prusa’s PETG guide provides process context.
ASA: review outdoor requirements specifically
ASA is often considered where UV exposure matters. That does not resolve every outdoor requirement: temperature, loading, water, finishes and interfaces still need review. Confirm the relevant grade’s data and the supplier’s process. Prusa’s ASA guide describes its UV resistance and printing considerations.
Compare evidence on the same basis
Check whether published values come from printed specimens or another manufacturing process. Note test direction, conditioning and the method used. A value from one test is not a universal allowable load for your part.
Agree the review or prototype work needed for uncertain requirements. Record the exact material and supplier in the handoff so a later substitution can be assessed rather than assumed equivalent.
9OneFour can help develop the design and organize the material questions as part of manufacturing preparation. Materials, prototypes and supplier involvement are scoped per project, without a public per-part price list or default material for every application.