How the angle of the turning tool determines the several angles of the turning tool
The turning tool is a single-edge tool, and there are many types due to the different shapes of the turning work, but it The names and functions of the parts are the same. A good turning tool must have two major parts: a rigid handle and a sharp blade. The blade angle of the turning tool directly affects the turning effect. Different turning tool materials and workpiece materials, and the angle of the blade are also different. The turning tool for lathe has four important angles, namely the front clearance angle, the side clearance angle, the back bevel angle and the side bevel angle.
1) Front clearance angle
The angle inclined from the nose to the inside of the cutter is the front clearance angle. A space is formed under the tool tip, so that the cutting action is concentrated on the tool nose. If the angle is too small, the tool will rub on the surface, resulting in a rough surface. If the angle is too large, the tool will easily vibrate, so that the nose of the knife cannot be polished. When installing a turning tool with an inclined middle handle, the angle of the handle should be considered. The angle of the high-speed steel turning tool is about 8~10 degrees, and the carbide turning tool is between 6~8 degrees.
2) Edge clearance angle
The angle at which the side of the tool is inclined from the cutting edge to the inside of the tool is the edge clearance angle. The edge clearance angle forms a space between the working surface and the side of the tool, so that the cutting action is concentrated on the cutting edge to improve the cutting efficiency. The angle of the high-speed steel turning tool is between 10 and 12 degrees.
3) Back bevel
The angle of inclination from the nose to the handle from the top surface of the knife is the back bevel. This angle is mainly used to guide chip evacuation and reduce chip evacuation resistance. For cutting general metals, high-speed steel turning tools are generally 8 to 16 degrees, while carbide turning tools are negative inclination or zero degrees.
4) Edge bevel
It is inclined from the cutting edge to the other side from the top surface of the tool, and the angle formed by this inclined surface and the horizontal plane is the edge bevel . This angle is the angle at which the chips are separated from the workpiece, making chip evacuation easy and efficient turning. For general metal cutting, the angle of the high-speed steel turning tool is about 10~14 degrees, while the carbide turning tool can be either positive or negative.
5) Tip Angle
The angle between the front end of the blade and the shank perpendicular to it. The function of this angle is to maintain a gap between the front end of the blade and the workpiece to prevent the blade from rubbing against the workpiece or scratching the machined surface.
6) Cutting edge angle
The angle between the front end of the blade and the shank perpendicular to the blade, which is used to change the thickness of the cutting layer. At the same time, the cutting corner can also change the force direction of the turning tool, reduce the feeding resistance and increase the tool life. Therefore, in general rough turning, a turning tool with a larger cutting corner should be used to reduce the feeding resistance and increase the cutting speed.
7) Nose radius
The radius of the edge arc of the highest point of the blade. The nose radius is large and strong, it is used for large cutting depth, but it is prone to high frequency vibration.
