In profile turning, the cut can vary with regard to cutting depth, feed and speed. Tools used for profile turning are subjected to large variations in stress and depth of cut due to the varying machining directions and diameter changes. One of the most important properties of a profiling tool is accessibility.
The largest suitable nose angle on the insert should be selected for strength and cost efficiency, but the insert nose angle has to be considered in relation to accessibility. The most frequently used nose angles are 35° and 55°.
Analyze the workpiece profile in order to select the most suitable entering angle. A free cutting angle of at least 2° between the workpiece and the insert has to be maintained. However, for reasons relating to surface finish and tool life, at least 7° entering angle (83° lead angle) is recommended.
First choice is a tool with 93° entering angle (-3° lead angle) and a D-style (55°) insert. If a larger ramping angle is needed, use a V-style (35°) insert.
For the possibility to profile in another direction or to make a corner relief, choose a holder with a 107–117° entering angle (-17 to -27° lead angle).
Turning tools for profile turning
In face turning, the tool is fed radially towards the centre, at the end of the workpiece. The radial cutting forces are high, which may generate deflection on the component and may sometimes also cause vibration.
The insert shape should be selected according to the required entering angle and in relation to the accessibility or versatility required for the workpiece. The largest suitable nose angle on the insert should be selected for strength and cost efficiency.
75° entering angle (15° lead angle)
A reduction of the entering angle, (increasing of the lead angle) can redirect some of the radial forces axially toward the chuck for better stability and reducing vibration tendency.
For optimization, choose a holder with a square insert and a 75° entering angle (15° lead angle).
For versatility, choose a holder with a rhombic 80° or trigon insert and a 95° entering angle (-5° lead angle).
Turning tools for face turning