Metric (MM) Nuts CHN are fasteners manufactured in China adhering to international metric standards (ISO, DIN, GB, JIS) rather than the imperial system. They are characterized by their “M” designation (e.g., M6, M8, M12), which indicates the nominal diameter in millimeters. These nuts are heavily used in construction, machinery, and automotive industries and are manufactured from materials like stainless steel, carbon steel, and brass.