Hiram is mentioned in three contexts in the Bible. In freemasonry Hiram Abiff is assocaited with a mason who worked on the temple of Solomon. Hiram Abiff and Hiram of Tyre, along wiht Solomon are the 3 grand masters of the Lodge of Jerusalem also called the Causal triad. There is considerable symbolic significance given to the three Hirams. http://en.wikipedia.org/wiki/Hiram_Abiff