Answer: vulcans

AnswerCrossword Clue
VULCANSGrandiose blacksmiths.
VULCANSSpace race
vulcansVULCAN, a blacksmith
vulcanshypothetical planet nearest the sun whose existence was erroneously postulated to account for perturbations in Mercury's orbit
vulcanssix-barrel, 20mm U.S. Army antiaircraft gun system mounted on an armored personnel carrier and first deployed in 1968