We present experimental flux-temperature phase diagrams for surface reconstruction transitions on the 6.1 Angstrom compound semiconductors. The phase transitions occur within or near typical substrate temperature ranges for growth of these materials by molecular beam epitaxy and therefore provide a convenient temperature standard for optimizing growth conditions. Phase boundaries for InAs (001) [(2 x 4) --> (4 x 2)], AlSb (001) [c(4 x 4) --> (1 x 3)], and GaSb (001) [(2 x 5) --> (1 x 3)] are presented as a function of substrate temperature and Group V-limited growth rate (proportional to flux), for both cracked and uncracked Group V species. We discuss differences between materials in the slopes and offsets of the phase boundaries for both types of Group V species.