How to choose the model of hard alloy thread end milling cutter

How to choose the model of hard alloy thread end mill? This is mainly related to the shape and hardness of the processed material.
Material hardness: If the hardness HRC of the cutting material exceeds 40, a two tooth or three tooth thread milling cutter should be used, while for machining below HRC40, a standard thread milling cutter should be used.
Internal or external thread selection: Some specifications of thread milling cutters have universal internal and external threads, such as metric M or American standard UN. The same thread milling cutter can process internal and external threads.
Thread length: The basic principle to follow is not to exceed 4 times the thread diameter of the thread length. If the thread length is less than 4 times, try to choose a solid hard alloy thread milling cutter. If it exceeds 4 times the diameter, non-standard cutting tools need to be customized.
Milling cutter diameter: Select a milling cutter diameter that is close to the specification of the threaded hole being processed
Select milling cutter materials based on the processed materials. For example, JK10CA is suitable for processing materials above HRC40 and some titanium alloys, stainless steel, high-temperature alloys, etc. JK20CB is suitable for processing soft materials below HRC40, and JK10F is suitable for processing materials such as non-ferrous metals.
Thread size: Choose whether to use a solid thread milling cutter or an indexable thread milling cutter. Generally, for sizes below M12, use a solid hard alloy thread milling cutter. For larger sizes, an indexable thread milling cutter is generally recommended. When the smoothness requirement is high, a solid thread milling cutter should be selected.
High hardness materials, particularly difficult to machine materials, deep hole threads, or threads that require high smoothness can usually be processed using external cold thread milling cutters.