We are Bygold. We focus on development, production and marketing our brand fasteners pre DIN, ANSI,ISO, and GB standards. The management and quality system has been certificated in ISO9001:2000, and 3.1 certificate. As the top of the professional class 12.9 bolts manufactures in the China . BYGOLD screws cover a wide range of products, including the alloy steel hex socket head cap screw, hexagon bolt, button head screws, flat head screw, Sus hex socket head set screw, shoulder screw, combination screw and so on. Through precision manufacturing and precise control of the hex socket size, accurate head forging makes the metal flow more uniform, the m...