Turning Technology and Classification of Copper Nuts

Copper nuts have many characteristics, such as being less prone to rust, anti-corrosion, easy to conduct heat, and strong conductivity. Copper nuts are generally used in environments such as rust prevention, high temperature, conductivity, and thermal conductivity, such as faucets, valves, electrical switches, etc. Another main use of copper nuts is injection molding, which is embedded into plastic parts after heating or directly molded for injection molding, as mentioned earlier. Below is an introduction to the turning technology and classification of copper nuts:
Classification of copper nuts
According to their purpose, they can be divided into three categories: machine screws, set screws, and special purpose screws.
Machine screws are primarily used for fastening threaded holes, and screws are also a type of fastener consisting of a head and a screw. The fastening connection between a part with a through hole does not require nut cooperation (this connection method is called screw connection, also known as detachable connection: it can also be used for fastening connection between two parts with through holes in collaboration with nuts.
The tightening screw is primarily used to fix the relative orientation between two parts.
Special purpose screws, such as eyebolts, are used for lifting parts. The shape is generally shown as a flat hexagonal column, with nuts and internal threaded holes. There are also flat square or flat column shaped collaborative bolts, studs, or machine screws used to tighten and connect two parts into one piece.
High strength self-locking copper nuts have high strength and are a classification of self-locking nuts. The strong side of reliability. The first step was to introduce European technology as a condition for use in road construction machinery, mining machinery, vibration machinery equipment, etc. At that time, there were very few domestic manufacturers producing such goods.
Nylon self-locking copper nuts can be used in various mechanical and electrical products at temperatures of -50100C. At that time, nylon self-locking nuts were a new type of high vibration and anti loosening fastening component. The demand for nylon self-locking nuts increased significantly in aerospace, aviation, tank, mining machinery, automotive transportation machinery, agricultural machinery, textile machinery, electrical goods, and various types of machinery. This is because its vibration and anti loosening function was much higher than other copper inserts.
Turning Technology
The turning technique of copper nut threads: There are two main methods of machining internal and external threads on the workpiece, namely cutting and rolling.
The application of the thread principle can be traced back to the invention of the spiral water extractor by Greek professor Archimedes in 220 BC. In the 4th century AD, Mediterranean coastal countries initially applied the principle of bolts and nuts to their brewing presses. At that time, the external threads were all wrapped with a rope onto a cylindrical bar material and then carved according to this symbol. The internal thread, on the other hand, is often wrapped in softer material and hammered into shape on the external thread.
In the sketches of thread processing equipment manufactured by Italian Leonardo da Vinci around 1500, there was already a fantasy of using female screw and communication gear to process threads with different pitches. Afterwards, the method of mechanical thread cutting was developed in the European clock manufacturing industry. In 1760, the British brothers J. Wyatt and W. Wyatt obtained a patent for using specialized equipment to cut wooden screws.
In 1778, British man J. Ramsden manufactured a thread cutting equipment driven by worm gear pairs, which could process long threads with high accuracy. In 1797, the British man Mozley H. used a lathe improved by him to turn metal threads with different pitches using a female screw and a communication gear, and established the basic method for turning threads.
In the 1820s, Mozley manufactured the first batch of taps and dies for processing threads. At the beginning of the 20th century, the development of the automotive industry further promoted the standardization of threads and the development of various precision and efficient thread processing methods. Various automatic opening plate heads and automatic shortening taps were successively invented, and thread milling was initially applied.
In the early 1930s, thread grinding emerged. Although thread rolling technology was patented in the early 19th century, it developed slowly due to difficulties in mold manufacturing until World War II (1942-1945), when the need for military production and the development of thread friction technology addressed the accuracy issues of mold manufacturing, which led to its rapid development.
(1) Thread cutting generally refers to the method of machining threads on workpieces using forming tools or grinding tools, mainly including turning, milling, tapping, threading, grinding, grinding, and whirlwind cutting. When turning, milling, and grinding threads, the transmission chain of the machine tool ensures that the turning tool, milling cutter, or grinding wheel moves accurately and evenly along the axial direction of the workpiece for one lead per revolution of the workpiece.
During tapping or threading, the tool (tap or die) rotates relative to the workpiece and is guided by the previously formed thread groove to move axially. Thread turning (thread turning): Turning threads on a lathe can be done using a forming turning tool or a thread chaser (see Thread Processing). Turning threads with formed turning tools is a common method for single and small batch production of threaded workpieces due to simple tool planning. Turning threads with thread combs has high production efficiency, but the tool planning is messy and only suitable for short threaded workpieces with fine teeth in medium to large batch production. The pitch accuracy of general lathe turning trapezoidal threads can only reach levels 8-9 (JB2886-81, the same below); Processing threads on specialized thread lathes can significantly improve yield or accuracy
(2) Thread milling (thread milling) is performed on a thread milling machine using a disc milling cutter or comb milling cutter. The disc milling cutter is mainly used for milling trapezoidal external threads on workpieces such as screw rods and worms. Comb shaped milling cutters are used for milling internal and external general threads and taper threads. Due to the use of a multi edge milling cutter for milling, some lengths of the operation are larger than the length of the processed thread. Therefore, the workpiece only needs to be rotated by 1.25 to 1.5 revolutions to complete the machining, resulting in a high production rate. The pitch accuracy of threads can generally reach levels 8-9, and the surface roughness is R5-0.63 micrometers. This method is suitable for mass production of threaded workpieces with general accuracy or rough machining before grinding.
(3) Thread grinding is mainly used to process precision threads of hardened workpieces on thread grinding machines. There are two types of grinding based on the different cross-sectional shapes of the grinding wheel: single line grinding wheel and multi line grinding wheel. The pitch accuracy that can be achieved by single line grinding wheel grinding is 5-6 levels, and the surface roughness is R1.25-0.08 micrometers. Grinding wheel dressing is relatively convenient.
This method is suitable for grinding precision screws, thread gauges, worms, small batch threaded workpieces, and precision hobs. Multi line grinding wheel grinding can be divided into two types: longitudinal grinding method and plunge grinding method. The width of the grinding wheel in the longitudinal grinding method is smaller than the length of the ground thread, and the grinding wheel can be moved longitudinally once or several times to grind the thread to the end standard. The grinding wheel width of the cut in grinding method is greater than the length of the ground thread. The grinding wheel radially cuts into the surface of the workpiece, and the workpiece can be ground by about 1.25 revolutions. The production rate is high, but the accuracy is slightly low. The grinding wheel dressing is relatively messy. The cut in grinding method is suitable for scraping and grinding large batches of taps and certain fastening threads.
(4) Thread grinding uses soft materials such as cast iron to make nut or screw type thread grinding tools, which perform forward and reverse rotation grinding on the parts of the processed thread on the workpiece with pitch errors to improve pitch accuracy. Hardened internal threads are generally ground to eliminate deformation and improve accuracy.
(5) Tapping and threading (tapping with a tap) are processes where the tap is screwed into a pre drilled bottom hole on the workpiece with a certain torque to produce internal threads. Thread threading (using die threading) is the process of cutting external threads on a rod (or tube) workpiece using a die. The machining accuracy of tapping or threading depends on the accuracy of the tap or die. Although there are many methods for processing internal and external threads, small diameter internal threads can only be processed with a tap. Tapping and threading can be done manually, as well as using lathes, drilling machines, tapping machines, and threading machines.
(6) Thread rolling is a processing method in which a forming rolling die is used to cause plastic deformation of the workpiece to obtain threads. Thread rolling is generally done on a thread rolling machine. Thread rolling machine or automatic lathe equipped with automatic opening and closing thread rolling head, suitable for mass production of external threads of standard fasteners and other threaded connectors.
The outer diameter of the rolled thread generally does not exceed 25 millimeters, and the thread accuracy can reach level 2 (GB197-63) when the length is not more than 100 millimeters. The diameter of the blank used is roughly equal to the pitch diameter of the processed thread. Rolling generally cannot process internal threads, but for workpieces with soft materials, a slotless kneading tap can be used to cold extrude internal threads (with a maximum diameter of about 30 millimeters). The operating principle is similar to tapping. The torque required for cold extrusion of internal threads is approximately twice that of tapping, and the machining accuracy and surface quality are slightly higher than tapping
The benefits of thread rolling are that the surface roughness is less than that of turning, milling, and grinding; The surface of the thread after rolling can advance in strength and hardness due to cold work hardening: high data utilization rate: production rate doubled compared to cutting processing, and easy to complete automation: the rolling die has a long lifespan. However, rolling threads requires that the hardness of the workpiece data does not exceed HRC40: the standard accuracy for roughening needs to be higher; The precision and hardness requirements for rolling molds are also high, making it difficult to manufacture molds: they are not suitable for rolling threads with asymmetric tooth shapes.