modern lance point, square cross section, fullers. the blade portion on it is about six inches and the socket about 3 in. when rough forged & before cleaning and polishing/sharpening it looks much like fernando's photos.
military pikes frequently had similar square cross section heads, especially naval boarding pikes. broad bladed sharpened edged leaf shaped spearheads were not needed on a pure thrusting pole-arm. most had languets running down the shaft from the socket as re-enforcement & to protect against sword blows.
flags were initially carried on lances, so i can envisage an old lance being used as a flag staff. age of course would tend to round the edges and point which was no longer used as a weapon.
photos and dimensions would be nice.
(fernando, is your post another example or is it a helpful posting of the original posters photos?)