These 8.8 grade fasteners comply with GB70 standard, featuring **left-hand/reverse thread** and black Dacromet coating for outstanding rust prevention, corrosion resistance and durability. Adopting fully threaded cylindrical cup head design with internal hex drive, they deliver high strength, stable clamping and reliable anti-loosening performance for special reverse-thread fastening scenarios. Widely used in machinery, equipment assembly, molds and precision devices where left-hand thread locking is required. Each screw is strictly inspected for thread accuracy and dimensional consistency. Available in full sizes with factory-direct supply, providing professional high-strength reverse thread fastening solutions.