The inclusion of engineering standards in US science education standards is potentially important because of how limited engineering education for K-12 learners is, despite the ubiquity of engineering in students' lives. However, the majority of learners experience science education throughout their compulsory schooling. If improved engineering literacy is to be achieved, then its inclusion in science curricula is perhaps the most efficient means. One significant challenge that arises, however, is in the framing of engineering relative to science by both teachers and curriculum. Science and engineering are both distinct and interdependent. The nature of the contributions of science and engineering to one another has been an area of some examination in philosophy of technology and engineering, but little framing of this relationship has been conducted with K-12 science and engineering education contexts in mind. Nature of science (NOS) is a critical layer of scientific understanding that has been used to explicitly support literacy in K-16 science classrooms for decades. However, engineering cannot be authentically and appropriately supported by NOS framing. There is an immediate need for discourse on the nature of engineering knowledge (NOEK) but not in isolation of NOS. Given the increasing inclusion of engineering in science classrooms, relationships between NOS and NOEK are in need of explication and argument. Our purpose is to promote a discussion about NOS, engineering, and the relationship between them without misrepresenting engineering as a subdomain of science or as an oversimplification of itself.