High strength@ low alloy steel represents a specific group of steels in which enhanced mechanical properties and@ in some cases@ resistance to atmospheric corrosion are obtained by the addition of moderate amounts of one or more alloying elements other than carbon. Different types are available@ some of which are carbon-manganese steels and others which contain further alloy additions@ governed by special requirements for weldability@ formability@ toughness@ strength@ and economics. Descriptions of the different grades are given in the paragraph entitled General Information. These steels may be obtained in the form of sheet@ strip@ plates@ structural shapes@ bars@ and bar size sections. These steels are especially characterized by their mechanical properties@ obtained in the as-rolled condition. They are not intended for quenching and tempering@ and the purchaser should not subject them to such treatment without assuming responsibility for the ensuing mechanical properties. For certain applications these steels are sometimes annealed@ normalized@ or stress relieved with some influence on mechanical properties. Where those steels are used for fabrication by welding@ care must be exercised in selection of grade and in the details of the welding process. Certain grades may be welded without preheat or postheat.