Hexagonal head bolt equipped with metric fine pitch thread. Compared with coarse thread bolts, fine thread has smaller pitch, larger minor diameter, better tensile capacity and stronger anti-loosening performance under vibration conditions. Available in partial thread and full thread versions. Strength grades: 4.8, 8.8, 10.9, 12.9. Materials include carbon steel, alloy steel and stainless steel A2-70 / A4-70. Surface treatments: black oxide, zinc plating, hot-dip galvanizing, Dacromet. Metric fine thread specifications complete. Widely used in automobile industry, precision machinery, hydraulic equipment, engineering machinery and occasions requiring high preload and vibration resistance.