【Summary】Copper has a long history of use, with our ancestors having mastered the smelting and processing of copper as early as the Shang and Zhou dynasties. Today, copper as an excellent conductive material can be found everywhere in everyday life.
Copper has a long history of use, with our ancestors having mastered the smelting and processing of copper as early as the Shang and Zhou dynasties. Today, copper as an excellent conductive material can be found everywhere in everyday life. In the fastener industry, copper and copper alloys are a widely used material due to their good electrical and thermal conductivity and corrosion resistance. Copper fasteners are used in the valve industry, electronics industry, electric power industry, machinery manufacturing, construction industry, transportation, defence industry, energy and petrochemical industry, new industries and high-tech fields, etc.
Classification of copper materials
Generally speaking, according to the composition can be divided into pure copper, brass, white copper, bronze.
Pure copper (purplish copper).
Pure copper is also known as "purple copper" because of its purplish red surface. The copper content of pure copper for general industrial use is 99.5%. Pure copper is an excellent conductive material second only to silver and is soft enough to be used in the manufacture of fastening joints and sealing gaskets with high requirements for electrical conductivity.
For example, DIN7603 A sealing washers JB/ZQ4454 screw plug with sealing washers; JB/ZQ4180 water with screw plug washers; copper plug, terminals, etc.
It is a copper-zinc alloy, common brass, to which other metal elements can be added to form a rich brass alloy system, for example, adding lead elements to form lead brass, adding manganese elements to form manganese brass. The choice of material varies according to the application and processing requirements. As the copper content changes, so do the alloy properties. Commonly used brasses such as H62 and H65, indicate a copper content of 62% and 65% respectively. And the higher the content of zinc in it, the strength of the material increases with it, but the plasticity then decreases. Brass is cheaper than purple copper, conductivity and plasticity is slightly worse than purple copper, but strength and hardness to high. Fastening industry more brass as fasteners with material, can manufacture brass bolts, brass studs, brass nuts, brass flat washers, brass spring washers, brass screw bushings, etc.. However, the zinc content in brass should be controlled within 45%, because the higher zinc content will lead to an increase in material brittleness, resulting in poor product plasticity and affecting product performance.
Leaded brass is also a common brass material for the manufacture of some machined and automatically turned parts. For example C3604, HPb59-1, etc., because the addition of lead content can improve its cutting properties and at the same time meet its performance requirements. It can be commonly used for the machining of copper hexagonal pillars, copper yin and yang screws, copper cap nuts, etc.
White copper is a copper-nickel alloy, silvery white in colour, with a nickel content of generally 25%. Manganese, iron, zinc and aluminium can also be added to the binary alloy common white copper to create complex white copper to achieve the relevant complex characteristics.
Refers to copper alloys other than brass and white copper and is often preceded by the name of the first major added element to the bronze name. Examples include tin bronze, lead bronze, aluminium bronze, beryllium bronze, phosphor bronze, etc.
Silicon bronze and phosphor bronze as a copper alloy with high strength and elastic properties of the representative, hardness can be greater than 192HV, commonly used to manufacture spring washers, conical washers and other parts.
Introduction to bolt strength classes
Strength grades are classified according to mechanical properties. According to the relevant standards, the bolt performance grade is divided into 3.6, 4.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9, 12.9 and more than 10 grades, of which 8.8 and above bolts made of low-carbon alloy steel or medium carbon steel and heat treatment (quenching, tempering), commonly known as high-strength bolts, the rest are commonly known as ordinary bolts. The bolt performance grade number has two parts consisting of numbers, which indicate the nominal tensile strength value of the bolt material and the flexural strength ratio. For example.MORE +
The first is the punching of the head, where the head of the screw is punched out of the wire and the wire is cut. The second is thread rolling, where two files are used to thwart the threads on top of the previous process.MORE +
Performance grades for hexagonal flange bolts
The bolt performance grade is composed of two numerical parts, which indicate the nominal tensile strength value and the flexural strength ratio of the bolt material.MORE +
What are the common automotive fasteners
Generally we use most of the fasteners belong to the type of general-purpose parts, its standard type is still quite high, the common fastener parts are the following 12 kinds:MORE +