Release time：2020-01-16 18:44 Browse：
In the field of machinery and engineering, lengthening screws, as an important connecting element, have a wide variety of functions and are widely used in the assembly and fixing of various equipment, structures and even precision instruments. These screws not only carry the heavy responsibility of transferring force and maintaining structural stability, but also show a variety of characteristics and application scenarios due to their different materials, surface treatment and strength levels. Below, we will delve into these main categories of lengthening screws and their characteristics.
First, material classification: stainless steel and carbon steel contest
Stainless steel extension screw
Stainless steel extension screws stand out for their excellent corrosion resistance and aesthetics. It is mainly composed of chromium, nickel and other alloying elements, which can maintain stable performance in a humid and corrosive environment for a long time and is not easy to rust. This material is especially suitable for Marine engineering, chemical equipment, food processing and other fields to ensure the safe operation of equipment in harsh environments. The hardness of stainless steel screws is moderate, easy to process, and has a certain tensile and shear resistance, which is the first choice for high-end equipment connection.
Carbon steel extension screw
Compared to stainless steel, carbon steel extension screws are known for their low cost and high strength. Carbon steel is mainly composed of iron and carbon, and its hardness and toughness can be adjusted by heat treatment to meet the connection tasks of different strength requirements. Carbon steel screws are widely used in construction, machinery manufacturing, automobile manufacturing and other industries, and are one of the most common types of screws in daily production and life. However, carbon steel screws are prone to rust in a humid or corrosive environment, so appropriate anti-corrosion treatment is required or the selection of galvanized, nickel plating and other surface treatments to enhance their corrosion resistance.
Second, surface treatment classification: improve performance and beauty
Dacromet treatment
Dacromet is an advanced metal surface treatment technology that forms a strong protective barrier by applying a dense zinc-chromium coating to the screw surface to effectively prevent screw rust and corrosion. Dacromet extension screws not only have excellent anti-corrosion properties, but also maintain good appearance and mechanical properties in harsh environments. This technology is widely used in automobiles, Bridges, electric power facilities and other occasions requiring long-term corrosion resistance.
Zinc-nickel alloy coating
Zinc-nickel alloy coating is another efficient anticorrosion method, which deposits a layer of zinc-nickel alloy coating on the screw surface by electrochemical method, which has higher corrosion resistance and longer service life than pure zinc coating. Zinc-ni alloy coating has good uniformity and adhesion, and can effectively resist the erosion of salt spray, moisture and other harsh environment. This kind of lengthening screw with surface treatment is widely used in aerospace, rail transit and other high-end fields.
Third, strength grade classification: to meet the needs of different loads
4.8 extension screws
4.8 extension screw is a lower strength grade of screw, its tensile strength and yield strength is relatively low, suitable for the connection strength requirements are not high occasions, such as furniture assembly, general mechanical equipment installation. These screws are low cost, easy to procure and install, and are one of the most widely used screws in daily life.
8.8 extension screws
Class 8.8 extension screws belong to the medium and high strength class, and their tensile strength and yield strength are higher than class 4.8, which can withstand greater load and torque. This screw is widely used in automobiles, heavy machinery, Bridges and other occasions requiring high strength connections. Class 8.8 screws not only have good mechanical properties, but also undergo a strict heat treatment process to ensure their stability and reliability under harsh conditions.
peroration
In summary, there are a wide variety of lengthening screws, and each type shows its unique advantages and scope of application according to its material, surface treatment and strength level. When selecting the extension screw, it is necessary to comprehensively consider the specific application scenario, load requirements and environmental conditions to ensure the safety and reliability of the connection. With the progress of science and technology and the development of technology, there will be more new materials and surface treatment technology in the future, providing a broader space and possibility for the application of lengthening screws.
# Stainless steel extension screws # Carbon steel extension screws # Zinc-nickel alloy extension screws #4.8 extension screws #8.8 extension screws
