1. General aspects

1.1 Economic importance of machining

Machining" refers to any operation involving the removal of material to give a part dimensions and a surface finish (shape deviation and roughness) within a given tolerance range.

From an economic point of view, the machining industry is of considerable importance, producing around 2.5% of a developed country's gross national product.

Machining primarily concerns metallic materials, and most metal objects in everyday use have undergone one or more machining operations. These operations form part of a succession of shaping operations at two main levels (figure 1 ):

• or as blank cutting...