Tool geometry is basically referred to some specific angles or slope of the salient faces and edges of the tools at their cutting point.

Both material and geometry of the cutting tools play very important roles on their performances in achieving effectiveness, efficiency and overall economy of machining. Cutting tools may be classified according to the number of major cutting edges (points) involved as follows:

• Single point cutting tools: Examples: turning tools, shaping, planning and slotting tools and boring tools.

• Double or two point cutting tools: Example: drills.

• Multi-point (more than two) cutting tool: Example: Milling cutters, Broaching tools, Hobs, Gear shaping cutters, etc.

The geometry of a single point cutting tool is determined by the following features:

Face or rake surface, which is the surface of cutting tool along which the chips move.

Flank surface that face the work piece. There are two flank surfaces, namely principal and auxiliary flank surface.

Cutting edge that remove material from the work piece. There are two cutting edges. The principal cutting edge performs the function of major material removal and is formed by the intersection line of rake face with the principal flank surface. The auxiliary cutting edge, often called as end cutting edge, is formed by intersection of rake face with the auxiliary flank surface.

Corner or cutting point, which is meeting point of the principal and auxiliary cutting edges. Often a nose radius is provided to avoid a sharp corner.

The above mentioned features are shown in the figure 1.