A cutting tool can never have its

Explanation

Explanation:- Clearance angle (α): The angle of inclination of clearance or flank surface from the finished surface. The clearance angle is essentially provided to avoid rubbing of the tool (flank) with the machined surface which causes loss of energy and damages to both the tool and the job surface. Clearance angle is a must and must be positive (3° - 15°) depending upon tool- work materials. Important Points R ​ = e ​ = viscousforce inertiaforce ​ μ ρVL F ​ = r ​ = ​ gravitation force inertia force ​ ​ Lg V E ​ = u ​ = ​ pressure force inertia force ​ ​ P/ρ V W ​ = e ​ = ​ surface tension inertia force ​ ​ σ/ρL V Rake angle (γ ): The angle of inclination of the rake surface from the reference plane. Rake angle is provided for ease of chip flow and overall machining. Rake angle may be positive, or negative, or even zero. Positive rake – helps reduce cutting force and thus cutting power requirements. Negative rake – to increase edge-strength and life of the tool Zero rake – to simplify the design and manufacture of the form tools. Clearance angle is essentially provided to avoid rubbing of the tool (flank)