... head screw spikes, timber drive spikes, T-bolts, fish bolts, switch & crossing bolts, high tensile strength bolts for rail bridges etc ... boiler steel. System metallurgical plants, railway bridges, airport hangar, port machinery, high-rise buildings, civil span. Structural steel tower masts ... HDG, Zinc, Black... Carbon steel: Grade/class 4.8, 5.8, 8.8, 10.9, 12.9... Stainless steel: SS201, SS304, SS316 ...