Atomweight  Atomweight (also referred to as light minimumweight, junior strawweight, junior mini flyweight and pinweight) is a weight class in combat sports. In women's boxing and junior amateur boxing pinweight is, or has been, a weight class for boxers weighing in under (before 2003, 45 kg). In September 2010 the women's class in amateur boxing was partly merged into an extended 45–48 kg light flyweight division, with women weighing less than 45 kg excluded from competition. Pinweight is still defined for junior contests. Current Champions  The atomweight division in mixed martial arts generally refers to competitors weighing less than 105 lb.