The production of threaded connections is a common application in the metalworking industry. Most products manufactured in the metalworking industry feature external 

or internal threads, with thread applications ranging from threaded screws to large pipe threaded joints associated with the oil and gas industry. There are many types of 

threads, and they also involve national standards and international standards. Each thread type differs in shape and size; each standard defines its specific thread type. 

In many cases, standard features of thread profiles meet the specific needs of an industrial segment or main application area. For example, UNJ and MJ thread profile 

standards are related to the aviation industry, and NPT and BSPT thread profile standards are related to pipelines, pipe joints and spare parts in the oil and gas industry.

Thread turning

Thread turning is one of the most efficient and common production methods for machining threads on rotating workpieces. Today's indexable insert market offers a wide 

variety of thread turning tools and inserts. It is advantageous to have different insert geometries and clamping methods to select the right insert for each application. 

A successful thread turning application depends on selecting the right threading tool. Correctly select indexable threading tools by following simple steps: first, confirm 

whether the process is an external thread or an internal thread, and further confirm whether you need to choose a right-hand tool or a left-hand tool; after selecting the 

.feed direction corresponding to the thread type Finally, the thread tool specifications need to be determined based on the workpiece drawing and application. Generally 

speaking, thread models are classified into metric or imperial based on thread type standards. In many cases, the thread model includes the following parameters: 

classification standard; pitch; number of thread heads; nominal diameter; thread length; tolerance grade. After collecting the effective thread diameter, pitch, and number 

of thread heads, the thread lead angle (helix angle) φ can be calculated. If a flat-mounted insert is used to provide the solution, the effective value of the thread lead angle

 (helix angle) φ is very important for the selection of the insert shim in the next step. For such tools, the value of the lead angle (helix angle) determines the choice of tool 

shim. (fig1) In addition to correctly setting the guide angle (helix angle) φ, the tool shim also plays a role in supporting the blade and protecting the tool when the blade is

 damaged. There are two thread insert types: full profile and universal profile. Full profile inserts are used to produce specific thread types, such as round threads (Rd) 

according to DIN 405 standard, BSW British Whitworth profile. General profile inserts require pre-turning of the outer circle of the workpiece or the bottom hole diameter 

of the inner hole.