... switch & crossing bolts, high tensile strength bolts for rail bridges etc.3, Various type and sizes of tie plates, ... pharmaceutical plants and steel boiler steel. System metallurgical plants, railway bridges, airport hangar, port machinery, high-rise buildings, civil ... and TCVN (Vietnam). steel structrue bolt1.Application:railways, highways, bridges, plants,etc. 2.Certificate:ISO9001:2008. 4.Also can ...