Plowshare

In agriculture, a plowshare (US) or ploughshare (UK; ) is a component of a plow (or plough). It is the cutting or leading edge of a moldboard which closely follows the coulter (one or more ground-breaking spikes) when plowing.

The plowshare itself is often a hardened blade dressed into an integral moldboard (by the blacksmith) so making a unified combination of plowshare and moldboard, the whole being responsible for entering the cleft in the earth (made by the coulter's first cutting-through) and turning the earth over.

In well-tilled terrain the plowshare may do duty without a preceding coulter.

In modern plows both coulter and plowshare are detachable for easy replacement when worn or broken. Provided by Wikipedia