This study explores how lexical bundles link smaller functional units (steps) in research article (RA) conclusions in hard and soft science knowledge fields by using corpus-based and corpus-driven approaches. RA conclusion corpora from the hard and soft sciences were compiled and four-word lexical bundles were extracted from each corpus. Conclusions containing lexical bundles were then imported into the UAMCorpus tool for manual tagging of functions, structures, moves, and steps associated with lexical bundles. It has been found that the four-word bundles play an important role in realizing the communicative purpose of the functional units in RA conclusions in both the hard and soft sciences. The results demonstrate that the resultative lexical bundle (e.g. the findings of the) is a strong indicator of the conclusions in both soft and hard sciences. Specific bundle structures and functions are identified as signalling different steps of the conclusions. The findings of this study add to the growing body of knowledge regarding the bundle-move connections and contribute to the construction of the RA conclusions in different disciplinary cultures.