High-Quality Galvanized Bolt Manufacturer

Common Materials: The base material is mostly steel. Low-carbon steel (such as Q235) is suitable for 4.8 grade ordinary bolts, while medium-carbon steel (such as 35# and 45# steel) is used for high-strength bolts. For special applications, hot-dip galvanized stainless steel is used, suitable for highly corrosive environments such as chemical and marine environments. While copper can also be used for galvanized bolts, its high cost limits its application to electrical connections.

Standards: For example, 8.8 grade hot-dip galvanized hexagonal bolts comply with GB/T5782 (semi-threaded) and GB/T5783 (fully threaded) national standards. Thread specifications cover M1.6 - M20 and above, with clear standard specifications for parameters such as pitch and length for different bolt sizes.

Special Considerations: The high temperature of hot-dip galvanizing may slightly affect the mechanical properties of high-strength bolts of grade 8.8 and above, requiring strict control of process parameters during production. Cold galvanizing, on the other hand, uses a low temperature process that does not alter the properties of the base material, making it more suitable for precision bolts or precision components requiring high strength. Furthermore, both processes require environmental protection measures: hot-dip galvanizing necessitates controlling zinc fume emissions, while cold galvanizing requires proper treatment of electroplating wastewater.