In this essay, I reflect on Joseph Needham's intellectual heritage, its impact on understanding the world history of knowledge circulation, and its broad influence on generations of scholars. I present two case studies of paktong and iron/steel to show what Needham himself achieved and what recent progress has been made, highlighting the change of research paradigm from a patriotic or nationalistic approach to a global history approach. I argue that Needham's work still sets a marker for ongoing research in many respects and that, especially, his cross-culturally comparative approach to global circulations of knowledge and technology remains of deep relevance to contemporary scholars.