Milling machine

When a thread is required to be very precise, it is rectified with grinding machines in machining centers (CNC), which allow profiles of all threading systems to be created and also have great precision since they are machines controlled by software to which an operator adds parameters, reducing costs and simplifying the work.

Thread milling makes it possible to thread harder materials and develop cutting and feed speeds much higher than tap threading. You can also perform various operations on holes, such as drilling a hole, countersinking, machining the thread, and grooving the end of the thread. You can make the thread reach closer to the bottom of a blind hole, and even tap holes of different dimensions in the same part.

A tap can only produce “the direction” of the thread—right or left—that has been milled into the tool. But the milling machine can produce threads in both directions by changing the CNC programming.

Chip control is greatly improved with thread milling. In addition, the thread mill can be adjusted radially to achieve a tolerance different from the theoretical one or to extend the life of the tool.

Lathe

Thread turning is frequently carried out on CNC lathes, with hard metal tools with interchangeable inserts that have already adapted the profile of the thread being machined.[2]​.

The machine advance intervals must coincide with their pitch, which is achieved with the programming of the CNC lathes. Turning with indexable inserts is performed by making several cutting passes along the entire length of the thread, dividing the total depth of the thread into small passes.

Rolling threading

When large quantities of threaded parts need to be produced, rolling is used instead of chip removal. In this method the fibers of the material are not cut but displaced. This reduces manufacturing time, extending the durability of the tools, in addition to reducing material leftovers.

Roll threading can be performed on various types of lathes, machining centers and CNC lathes. Here the diameter of the thread flanks is taken into account. The mechanical and functional characteristics of cemented and tempered screws with metric threads are found in the ISO 7085:2000 standard.

The sum of the raw material cost of a part, the cost of the machining process, and the cost of defectively manufactured parts constitute the total cost of a part. Technological development allows us to obtain the highest possible quality of components at the lowest cost of both raw materials and machining. To reduce costs, soft materials are obtained that after machining are hardened by thermal treatments that increase their hardness and resistance, among other mechanical properties.

Costs are also reduced with better machining tools that improve the technological conditions of machining (for example, more revolutions of threading tools or longer edge life).

Numerical control reduced the rate of defective parts, almost eradicating manual threading. This is applied, for example, in the manufacture of standardized screws and nuts because in a very short time a large number of pieces can be produced with very good quality and at a low price. It has not been the same with the threading of holes, both blind and through, because before threading the hole must be drilled and it must match the characteristics of the thread.

Threads can be measured or checked directly or indirectly. For direct measurement, micrometers "Micrometer (instrument)") with adapted tips that are inserted into the flank of the threads are generally used. A set of rods can also be inserted to measure the average diameters.

For the indirect measurement of threads, several methods are used, such as gauges, which are composed of two parts that allow measuring both male and female threads. Another type of gauge is a set of templates that present the thread pitches of the different systems. Profile projectors are also used in metrology laboratories, which allow precision threads to be verified.

The threads can have various defects. The first is associated with its calculation and design. The thread dimensions, the right system and the right material may not have been properly selected. This causes premature or even sudden deterioration of the tightening.

The thread can also deteriorate due to corrosion or oxidation, which results in a loss of clamping pressure and could cause a failure due to the assembly becoming loose. Additionally, if the tightening exceeds the limiting torque of the threaded element, lamination of the most labile component of the torque may occur.

Milling machine

When a thread is required to be very precise, it is rectified with grinding machines in machining centers (CNC), which allow profiles of all threading systems to be created and also have great precision since they are machines controlled by software to which an operator adds parameters, reducing costs and simplifying the work.

Thread milling makes it possible to thread harder materials and develop cutting and feed speeds much higher than tap threading. You can also perform various operations on holes, such as drilling a hole, countersinking, machining the thread, and grooving the end of the thread. You can make the thread reach closer to the bottom of a blind hole, and even tap holes of different dimensions in the same part.

A tap can only produce “the direction” of the thread—right or left—that has been milled into the tool. But the milling machine can produce threads in both directions by changing the CNC programming.

Chip control is greatly improved with thread milling. In addition, the thread mill can be adjusted radially to achieve a tolerance different from the theoretical one or to extend the life of the tool.

Lathe

Thread turning is frequently carried out on CNC lathes, with hard metal tools with interchangeable inserts that have already adapted the profile of the thread being machined.[2]​.

The machine advance intervals must coincide with their pitch, which is achieved with the programming of the CNC lathes. Turning with indexable inserts is performed by making several cutting passes along the entire length of the thread, dividing the total depth of the thread into small passes.

Rolling threading

When large quantities of threaded parts need to be produced, rolling is used instead of chip removal. In this method the fibers of the material are not cut but displaced. This reduces manufacturing time, extending the durability of the tools, in addition to reducing material leftovers.

Roll threading can be performed on various types of lathes, machining centers and CNC lathes. Here the diameter of the thread flanks is taken into account. The mechanical and functional characteristics of cemented and tempered screws with metric threads are found in the ISO 7085:2000 standard.

The sum of the raw material cost of a part, the cost of the machining process, and the cost of defectively manufactured parts constitute the total cost of a part. Technological development allows us to obtain the highest possible quality of components at the lowest cost of both raw materials and machining. To reduce costs, soft materials are obtained that after machining are hardened by thermal treatments that increase their hardness and resistance, among other mechanical properties.

Costs are also reduced with better machining tools that improve the technological conditions of machining (for example, more revolutions of threading tools or longer edge life).

Numerical control reduced the rate of defective parts, almost eradicating manual threading. This is applied, for example, in the manufacture of standardized screws and nuts because in a very short time a large number of pieces can be produced with very good quality and at a low price. It has not been the same with the threading of holes, both blind and through, because before threading the hole must be drilled and it must match the characteristics of the thread.

Threads can be measured or checked directly or indirectly. For direct measurement, micrometers "Micrometer (instrument)") with adapted tips that are inserted into the flank of the threads are generally used. A set of rods can also be inserted to measure the average diameters.

For the indirect measurement of threads, several methods are used, such as gauges, which are composed of two parts that allow measuring both male and female threads. Another type of gauge is a set of templates that present the thread pitches of the different systems. Profile projectors are also used in metrology laboratories, which allow precision threads to be verified.

The threads can have various defects. The first is associated with its calculation and design. The thread dimensions, the right system and the right material may not have been properly selected. This causes premature or even sudden deterioration of the tightening.

The thread can also deteriorate due to corrosion or oxidation, which results in a loss of clamping pressure and could cause a failure due to the assembly becoming loose. Additionally, if the tightening exceeds the limiting torque of the threaded element, lamination of the most labile component of the torque may occur.