Specifications: 1) Size: a) Diameter: 3.5mm - 5.2mm, 6# - 14# b) Length: 19 - 150mm, 1" - 4" 2) Material: C1018 / C1022 hardened steel Inner packing: 100pcs - 1,000pcs/box Outer packing: 20 - 25kg/ctn