Tool Life :-

• Tool life is a most important factor in the evaluation of machinability, it is the period of time in which the tool cuts effectively and efficiently.

• Tool life refers to the useful life of a machine tool. It can be expressed in the amount of good parts that a given tool is capable of machining.

• Tool life is defined as the time period between two successive grinding of tool and two successive replacement of tool. A cutting tool should have long tool life.

• The cost of grinding and replacement is very high, so the short tool life will be uneconomical. Now a day’s tool material improvement increases the tool life.

Machinability :-

• Machinability is a characteristic of a material, such as a metal, that makes it easy to drill, shape, cut, grind, etc.

• The term machinability refers to the ease with which a metal can be machined to an acceptable surface finish.

• Machinability defines the ease at which a material (mainly metal) can be cut or shaped while providing a satisfactory surface finish.

• A material with good machinability requires little power to cut, produces a smooth surface finish and minimizes wear on the tooling.