Tool selection for thread processing

There are all kinds of cutting tools for processing thread holes, common thread turning tool, tap, squeeze tap, thread milling cutter and so on. How to select the correct processing tool, tool selection is actually the choice of processing method, each processing method used by the numerical control tool has different, for the processing of thread holes, there are several common ways: tapping, turning, extrusion molding and thread milling. Here we come to understand the advantages and disadvantages of various process methods and the use of restrictions, in actual production, we can according to the characteristics of these processing methods, from the technical and economic point of view to analyze the use of which tool for processing.

1. Tapping

Tapping is a widely used method in thread hole machining. It can determine the shape of the thread with the help of the geometric shape of the cutting tool, so there is no special machine tool when processing, it can be used in ordinary machine tools, production line machines and machining centers. Tapping is the process of tapping the first positive turn for cutting, to the bottom of the thread reverse, leave the workpiece, in a very narrow space for cutting and chip discharge, for different processing conditions, different processing properties, the selection of tap type is also different. Tap tapping is used in small diameter and mass production.

2. Turning processing

Turning thread is a triangular thread that is commonly used in production and is turned using a indexable cutting tool. The shape of the cutting part of the thread turning tool should be consistent with the axial section of the thread. When turning, every turn of the workpiece, the tool must move a lead lengthwise in order to process the correct thread.

3. Extrusion molding processing

Extrusion processing belongs to no chip processing, processing process and tapping the same, extrusion tap into pre-drilling, in the axial and radial extrusion material, so as to form a unique tooth type thread wheel. Thread extrusion molding is suitable for good plastic deformation of the material, the material range is relatively small, generally requires that the fracture elongation of the material is greater than 7%, and the maximum tensile strength is less than 1300, in the aluminum alloy processing application

4.Thread milling

Thread milling cutter is generally first down to the bottom of the thread hole, using the method of thread interpolation close to the workpiece, along the thread hole rotation 360 degrees and then Z axis direction up a pitch, and then leave the workpiece. Screw end milling cutter machining torque is small, increase the safety of the process. It also has a wide range of trials, can be machined in a variety of materials, and with the same pitch, using cutting tool can be machined in a variety of thread diameters or tolerance range. The disadvantage is that the machine tool is the three coordinates of CNC machine tool, in addition, relative to the tap, the processing efficiency is relatively low, the cutting tool cost is relatively high, so the trial in small batch production of large diameter thread hole processing.