What are the main processes that Carbon Steel Roofing Screw go through during the production process?

The production of Carbon Steel Roofing Screw begins with the selection of high-quality carbon steel materials. These materials, such as 45 steel or 60 steel, are known for their high strength and excellent durability, and are ideal base materials for manufacturing roof screws. When selecting raw materials, it is necessary to ensure that their chemical composition, physical properties and surface quality meet production standards to lay the foundation for high-quality products.
The carbon steel wire is stretched through a die to adjust its diameter to the required specifications. This process helps to improve the internal structure of the wire and improve its plasticity. The rough-drawn wire is heated to a certain temperature, kept warm for a period of time, and then slowly cooled. This step is designed to eliminate work hardening, reduce the hardness of the wire, and improve its ductility and plasticity in preparation for subsequent forming processing.
An acid solution is used to remove impurities such as oxides and oil stains on the surface of the wire to expose the metal matrix. A dense phosphate film is formed on the surface of the wire after pickling. This film not only enhances the bonding strength of the wire with the subsequent electroplating layer, but also improves the corrosion resistance of the wire.
The processed wire is fed into the cold heading machine, and the wire is cut into the required length through the stamping action of the die, and the nut and logo are formed at the same time. This process requires precise die design to ensure that the shape, size and logo of the screw head meet the standards. On the semi-finished product after cold heading, the thread is processed to the screw shank through the interaction between the active and fixed tooth plates of the thread rolling machine. This step requires the thread shape, pitch, accuracy, etc. to meet the design requirements to ensure the fastening and sealing performance of the screw.
Before heat treatment, the screw is cleaned to remove impurities such as oil and dust on the surface to ensure the heat treatment effect. The screw is heated to the carburizing temperature and kept warm for a period of time so that carbon atoms penetrate from the carburizing medium to the surface layer of the screw. This process is designed to improve the hardness and wear resistance of the screw surface. The carburized screw is quickly cooled to room temperature or low temperature to form a layer of hard martensitic structure on the screw surface. The cooling rate and temperature must be strictly controlled during the quenching process to avoid cracks and deformation. After quenching, the screw is cleaned to remove the quenching medium and impurities on the surface. Heat the quenched screws to a low temperature range and keep them warm for a period of time. This step is intended to eliminate quenching stress, improve the plasticity and toughness of the screws, and maintain the high hardness of their surface.
Before electroplating, the screws are pretreated, such as degreasing and rust removal, to ensure the bonding strength and quality of the electroplating layer. The pretreated screws are immersed in an electrolyte containing the required electroplating metal and an electric current is passed through them. Under the action of the electric field, the electroplated metal ions are reduced and deposited on the surface of the screws to form a metal plating layer. Common electroplating methods include zinc plating, nickel plating, etc. to improve the corrosion resistance and aesthetics of the screws. After electroplating, the screws are cleaned, dried, etc. to remove the plating solution and impurities on the surface and protect the electroplating layer from damage.