1. High speed steel thread turning tool
The profile angle of ordinary thread is 60 degrees, and that of inch thread is 55 degrees. In order to ensure accurate tool tip angle, thread angle sample vehicles can be used during grinding. When measuring, fit the tip of the knife with the template, aim at the light source, carefully observe the gap between the two fits, and conduct grinding. Special attention should be paid to the thread turning tool with longitudinal rake angle. Use a thick thread template to measure the sharp angle. When measuring, the template should be parallel to the bottom surface of the turning tool, and check with the light transmission method, so that the measured angle is approximately equal to the tooth angle.
The rake angle of the thread is generally 0-15 degrees. Because the longitudinal rake of the thread turning tool has a great impact on the tooth shape angle, the radial rake angle of the thread with high precision requirements is smaller, about 0-5 degrees.
The back angle is generally 5-15 degrees. Because of the influence of the rising angle of the thread, the back angle on the side of the feed direction should be slightly larger. However, for large diameter and small pitch triangular threads, this effect can be ignored.
High speed steel triangular external thread turning tool should grind out reasonable front and rear angles according to the requirements of rough and fine turning. The left and right blades of the turning tool must be straight without jumping blades. The cutter head is not skewed, and the tooth half angles are equal. The bisector of the sharp angle of the internal thread turning tool must be perpendicular to the tool bar. The rear angle of the internal thread turning tool should be appropriately larger. Generally, there are two rear angles when grinding.
Grinding tells steel turning tools to choose No. 80 alumina grinding wheel. When sharpening the tool, the pressure should be less than that of the general turning tool. If you feel hot and hot, you must use water to cool it in time, otherwise it is easy to cause the tip annealing.
2. Carbide triangle external thread turning tool
When turning threads with large pitch and high hardness, the carbide triangle external thread turning tool grinds chamfers with a width of 4mm on the two cutting edges of the turning tool. Because the actual tooth angle will expand when cutting threads at high speed, the tool tip angle should be reduced by 30 degrees. The surface roughness of the front and rear cutting surfaces of the turning tool must be very small.
When sharpening carbide thread turning tools, attention should be paid to the sharpening sequence. Generally, the back of the tool head should be roughly ground first, and then the two sides should be sharpened to avoid the bursting of the tool tip. During fine grinding, attention should be paid to prevent the blade from being broken due to excessive pressure, and prevent the blade from being damaged due to sudden cooling and heating during grinding.