Steels manufactured in around 1920 contain more sulfur and phosphorus comparing with present steels contain. Steels used in a bridge for a long term were welded by using a general filler wire, no defects or cracks occurred without dealing with special treatment like as pre-/post-heating. The welded joints with steels used for a long term had enough mechanical properties comparing with SM400A welded joints had. In the welded joints with steels used for a long term, Charpy absorbed energy was the smallest in the base metal. Brittle fracture percentage of the base metal was extremely high comparing with that of SM400A. Even if welding was used for joining in repair/reinforcement on the existing steel bridges, there were no problems in the welded joints. It was rather necessary that the base metal should be much noted.