Though software development has increasingly become a part of modern engineering practice, even outside of computing, we lack a sufficiently deep understanding of how engineers in many disciplines learn and use software engineering practices and tools (SEPTs). SEPTs are related to, but distinct from, programming itself, consisting of practices (e.g., unit testing) and tools (e.g., version control software) that support the design, implementation, or maintenance of software. While many disciplines outside of computing teach programming in their undergraduate curricula, little is known about how these disciplines use, teach, or adopt SEPTs. We thus conducted an exploratory qualitative study on SEPTs among undergraduate students in mechanical engineering (ME), one of the largest engineering disciplines in the US. Specifically, we explored two research questions: (1) What SEPTs do undergraduate ME students use in their work? (2) What factors influence undergraduate ME students’ adoption of these SEPTs? We conducted and analyzed three unstructured interviews with ME students at different institutions, using the Guide to the Software Engineering Body of Knowledge (SWEBOK) and the Unified Theory of Acceptance and Use of Technology (UTAUT) as theoretical frameworks. Our results show that ME students’ SEPTs span few SWEBOK areas, and are strongly influenced by course design, disciplinary context, and expected time/effort. These results suggest that with continued work in this area, we can likely gain and apply evidence-based insights to improve the teaching of SEPTs within ME in a way that is authentic to its disciplinary context.