JIS G3101 SS400 Steel . SS400 steel is the most commonly used hot-rolled structural steel (formerly known as SS41) in Japan, and is called general structural rolled steel in JIS G3101. SS400 material is cheap and versatile, and plays an important role in construction, bridges, civil engineering and Australia AS 1397 G300 / G300 Datasheet australia standard g300 grade structural t pipe steel for