From The Art and Popular Culture Encyclopedia
The head may be simply the sharpened end of the shaft itself, as is the case with bamboo spears, or it may be made of a more durable material fastened to the shaft, such as flint, obsidian, iron, steel or bronze.
The most common design for hunting or combat spears since ancient times has incorporated a metal spearhead shaped like a barbed triangle, lozenge or leaf. The heads of fishing spears usually feature barbs or serrated edges.
Spears can be divided into two broad categories: those designed for thrusting and those designed for throwing.