1.8 metres (six feet) in length. The shaft was generally made from ash while the head was usually of iron, although early republican hastae also had tips made of bronze. Javelin Although Romans often used the word pila to refer to all thrown javelins, the term pilum also means specifically the heavy Roman throwing javelin of the legions. Lighter, shorter javelins existed, such as those used by the velites and the early legions, called verutum. Other types of javelins were adopted by the late Roman army, such as the lancea and the spiculum, which were heavily influenced by the weapons of Italic warriors. Pilum The pilum (plural pila) was a heavy javelin commonly used by the Roman army in ancient times. It was generally somewhat less than long overall, consisting of a wooden shaft from which projected an iron shank about in diameter and long with a pyramidal head. The iron shank was socketed or, more usually, widened to a flat tang. A pilum usually weighed between , with the versions produced during the empire era being somewhat lighter. Pila were designed to penetrate both shield and armour, wounding the wearer; but, if they simply stuck in a shield, they could not easily be removed. Some believed that the iron shank would bend upon impact, weighing down the enemy's shield and also preventing the pilum from being immediately re-used. Some versions of the shaft may have fallen off on impact, leaving the enemy with a bent shank in their shield. However, recent evidence suggests that many types of pilum did not bend at all, but reduced the effectiveness of enemy shields by simply getting stuck due to the shape of its larger head and thin shank. In fact, there were many cases where the whole shank was hardened, making the pilum more suitable as a close quarters melee weapon, while also rendering it usable by enemy soldiers. Newer work by M. C. Bishop states that the pila are "unlikely to bend under their own weight when thrown and striking a target or ground" - rather, it is human intervention [e.g., improper removal of a pilum stuck in a target] that is responsible in some way, and that Caesar's writings should be interpreted as the pilum bent when soldiers tried to remove them. A sturdy pilum that does not bend upon impact would be in line with the numerous historical Roman