Turning inserts are high-efficiency inserts used for semi-finishing and finishing turning. Due to the scientific change of the radius of the rounded tool tip (its tool tip radius is composed of 

approximately 3 to 9 different radii), this will increase the contact length and have a positive impact on the feed rate or surface quality.

The wiper edge is the transition between the main cutting edge and the secondary cutting edge, and is actually an extreme form of the secondary cutting edge. It mainly plays the role of 

increasing the impact resistance of the tool tip and reducing the surface roughness value of the workpiece.

The secondary deflection angle of the wiper edge is generally 0° to 3°, and the length is 1.1 to 1.5 times the feed rate. Under normal circumstances, the shape of the wiper edge is arc-shaped 

and straight-line-shaped.

The increase in the radius r of the tool tip arc can improve the smoothness of the machined surface and the durability of the tool; but it will also increase the grinding force and easily generate 

vibration. For high-speed grinding steel turning tools, r is 0.5 to 5mm; for carbide turning tools, r is 0.5 to 2mm. R takes a small value for fine turning and a large value for rough turning. For 

general lathes, the value does not exceed 2mm.

The surface roughness value is because it has a secondary rake angle close to zero. However, this secondary rake angle depends on the shape of the blade and the size of the main rake angle 

of the tool holder. When the main rake angle changes, the secondary rake angle will also change, which means that the effect of polishing will be reduced or lost. The main rake angle is usually

recommended to be 95°.

Workpiece material

When processing plastic metals, low carbon steel, and non-ferrous metals, the machined surface often has a matte surface similar to abrasions. There are two main reasons for this, one is 

caused by built-up edge; the other is caused by the polishing edge (the contact length between the tool tip and the workpiece is longer than that of the standard blade), but this problem can 

be solved by increasing the cutting speed.