These flange bolts are made of high-quality 40CR alloy steel, heat-treated to **Grade 8.8** high strength, with outstanding tensile strength, shear resistance and good toughness, suitable for long-term heavy-duty fastening. The surface is treated with blue white zinc plating, which effectively improves rust and oxidation resistance, adapting to various general industrial environments. In full compliance with GB5789 standard, it adopts an **integrated flange design** that replaces independent washers, enlarges the stress area, enhances anti-skid and anti-loosening performance, and avoids loosening under vibration. The threads are precisely rolled with good fit, stable connection and easy installation. It provides full thread and half thread options, complete conventional specifications, widely used in construction machinery, automobiles, mechanical equipment, steel structures, electrical cabinets and other industrial fastening scenarios. Strict quality inspection ensures stable performance and accurate dimensions. Factory direct supply with sufficient stock supports wholesale and bulk orders, offering cost-effective, durable and reliable high-strength fastening solutions for industrial customers.