... 12.9 1, Elastic rail clips2, Dog spikes, square head screw spikes, timber drive spikes, T-bolts, fish bolts, switch ... Size from: M5 - M42 Length: 10mm-200mm Hexagon head bolt: Treatment: HDG, Zinc, Black... Carbon steel: Grade ... Also can manufacture by requirement. Steel structure hexagon head bolts TypeGradeMaterialSpecificationHardnessBolt10.9S20MnTiBM12-M30HRC33-3935VB8.8S40BHRC24-3145#35#Nut10H45 ...