share

A share is the primary cutting element of a plough, cultivator, or other soil-working machine. It is a shaped blade, usually of hardened steel, that penetrates the soil and either cuts through it, turns it over, or moves it sideways depending on the machine's purpose and the share's geometry. The share does the fundamental work of soil disturbance; everything else on the machine is built around supporting and positioning it effectively.

Shares take several basic forms. A plough share is typically a flat or slightly curved blade with a sharp leading edge and a socket or tang by which it attaches to the plough body. A cultivator share is narrower and may be straight, V-shaped, or reversible (double-ended to extend wear life). A lister share is wider and works in pairs to create a furrow. The angle at which a share is set, its width, and its thickness all affect how much force is needed to pull it through the soil and how well it cuts versus sliding.

Wear and failure modes

Shares wear continuously; the leading edge dulls, develops a rounded toe, and gradually loses its cutting action. Once dull, a share requires more draft force, compacts the soil more, and tends to skid rather than cut cleanly. Soil with stones, roots, or hardpan causes rapid dulling and can crack or break a share entirely. Replacement or resharpening is routine maintenance. Many farm operations keep spare shares on hand and swap them between machines or replace worn ones seasonally.

The term share derives from Old English and Germanic roots meaning to cut or divide. It has been used for the ploughshare since at least medieval times. In modern trade catalogues, shares are usually sold separately from the plough body and identified by crop type, soil condition, and machine model. A share intended for clay soil is built differently from one designed for light, sandy ground.

Material composition matters significantly. Standard shares are made from medium-carbon steel (around 0.40 to 0.60 percent carbon) that is hardened at the working edge to resist abrasion but left softer at the shank to absorb shock. Some modern shares have a hardened nose welded or bolted to a softer body to balance durability and cost. Stainless shares exist for special applications, though they are less common and more expensive.