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Turning tools are among the most widely used cutting tools in machining.

Turning tools are among the most widely used tools in machining. The working part of a turning tool is the part that generates and processes chips, including the cutting edge, structures that break or curl chips, spaces for chip evacuation or storage, and coolant channels.

The cutting part of a turning tool consists of the main cutting edge, auxiliary cutting edge, front rake face, main back rake face, auxiliary back rake face, and tip angle. The connection methods between the cutting part and the shank (clamping part) of a turning tool mainly include integral, welded, mechanically clamped, and welded-mechanically clamped types. Mechanically clamped turning tools can avoid stress and cracks in cemented carbide inserts during high-temperature welding, and the tool holder can be reused multiple times. Mechanically clamped turning tools generally use screws and clamping plates to clamp the insert, such as those with indexable inserts. After the cutting edge becomes dull, it can be indexed and reused, and the tool change time is short, thus achieving rapid development.

Composition

The cutting part of a turning tool consists of the main cutting edge, auxiliary cutting edge, front rake face, back rake face, and auxiliary back rake face. Its geometry is determined by the rake angle γo, back rake angle αo, main relief angle κr, side relief angle γS, auxiliary relief angle κr', and tip radius rε. The selection of turning tool geometry parameters is affected by many factors and must be selected according to the specific situation. The rake angle γo is selected according to the composition and strength of the workpiece material. For materials with higher cutting strength, a smaller value should be selected. For example, when a cemented carbide turning tool cuts ordinary carbon steel, the rake angle is 10°～15°; when cutting chromium-manganese steel or quenched steel, it is -2°～-10°. Generally, the back rake angle is 6°～10°. The main relief angle κr is determined by the rigidity of the machining system, generally 30°～75°. A larger value is selected when the rigidity is poor. When turning stepped shafts, due to the requirements of the cutting method, a value greater than or equal to 90° is selected.

Material

The tip radius rε and auxiliary relief angle κr' are generally selected according to the requirements of the surface roughness of the machined surface. The side relief angle γS is determined according to the required chip flow direction and cutting edge strength. The shape of the front of the turning tool (Figure 2) is mainly determined by the properties of the workpiece material and the tool material. The simplest is the plane type, and the positive rake plane type is suitable for high-speed steel turning tools and cemented carbide turning tools used for finishing. [1]

Knife Classification

Tools for machining various external surfaces include turning tools, planing tools, milling tools, external broaching tools, and files; tools for hole machining include drills, reamers, boring tools, reamers, and internal broaching tools;

2023

10-25

Cutting tool material selection

The material used to manufacture knives must possess high hot hardness and wear resistance, necessary bending strength, impact toughness and chemical inertness, good processability (cutting, forging and heat treatment, etc.), and not be easily deformed. Usually, when the material hardness is high, the wear resistance is also high; when the bending strength is high, the impact toughness is also high.

2023

10-25

Thread processing method

Thread processing is a process that uses tools to create threads. It employs cutting, turning, milling, grinding, and other processes to machine workpieces. It generally refers to the method of machining threads on workpieces using forming tools or abrasives. Main methods include turning, milling, tapping, die threading, grinding, polishing, and whirl cutting. When turning, milling, or grinding threads, the machine's transmission chain ensures that the cutting tool, milling cutter, or grinding wheel moves accurately and evenly along the workpiece's axial direction by one lead for each revolution of the workpiece.

2023

10-25