The seat of a Windsor chair is an essential part since it provides the stability to both the upper and lower portions. The thickness of the seat allows the legs to be anchored securely into their respective tapered sockets, providing the undercarriage with strength and stability. A timber that will provide the strength and stability whilst also allowing it to be shaped, in order to achieve the desired look and feel, requires a strong durable timber, with interlocking grain, to provide the right characteristics. English Windsors typically have elm seats because its interlocking grain gives good cross-grain strength that resists splitting where holes are placed close to the edge of a seat. There are no real satisfactory alternatives to elm although other woods have been tried, for example, oak and ash in Britain and various types of pine in the USA. Because of elm's strength compared to pine, tulip poplar or bass, English Windsor chair seats are usually not as thick as American Windsors. The English Windsor chair seats are not saddled (or dished) as deeply as their American counterparts- partly because of elm's relative strength, and partly because elm is comparatively more difficult to sculpt than the softer woods chosen by American chair makers. Woodwrights use tools such as the adze, scorp or inshave to form the hollowed out, form fitting, ergonomic top of the seat.