u bolt 1)material:mild steel,45#steel,40Cr steel 2)surface:painting,,, 3)size:M12-M32 4)grade:8.8,10.9,12.9 painting u bolt, round u bolt, leaf spring u bolt Certificate: ISO9001:2000High quality strengthen: Grade 8.8, 10.9, 12.9Material: mild steel, 45# steel, 40Cr steel, 35 Cr Mo steelThread pitch: 1.5mm, 2.0mm, 3.0mmsize:M12-M32Supply ability: 500 metric tons per monthFinishing: painting, zinc ...