"做粗活的工人" can be translated into English as "manual laborer" or "unskilled laborer".
"Manual laborer" emphasizes the physical nature of the work, referring to someone who performs tasks primarily with their hands or through physical effort.
"Unskilled laborer" highlights that the work does not require specialized skills or training, which can sometimes align with the idea of "粗活" (rough or unskilled work).
Both terms are appropriate depending on the context, but "manual laborer" is more commonly used and broadly applicable.