I would assume that on the Cold Steel hammer, it's purely for aesthetic purposes, though. Screwing them into the wood is a pain in the ass and personally I think in this case they are more of a hindrance.The "flanges" are actually langets and they keep the handle from getting fucked up when people parry strikes with swords and stuff and help keep it in one piece of the handle breaks.
In fact I think the only reason they are included with the war hammer is to keep the head on. The flanges are actually separate pieces and not attached to the head at all. Dang, why'd you cut the ears off? Or flanges.