1, pressure vessel steel plate: with a capital R at the end of the grade, the grade is available yield point can also be used carbon content or containing alloying elements said. Such as: Q345R, Q345 yield point. Another example: 20R, 16MnR, 15MnVR 15MnVNR 8MnMoNbR MnNiMoNbR 15CrMoR are carbon content or containing alloying elements. , Welding gas cylinder with steel: uppercase HP the end of its steel grades with yield point, such as: Q295HP Q345HP; also available with alloying elements such as: 16MnREHP to represent. 3 boiler plate: lowercase g at the end of the grades. The grade is available yield point, for: Q390g; carbon content can also be used or containing alloying elements, such as 20g, 22Mng, 15CrMog 16Mng 19Mng 13MnNiCrMoNbg 12Cr1MoVG. The bridge steel: lowercase q at the end of the grades, such as Q420q, 16Mnq, 14MnNbq. 5, automobile beam steel plate: with a capital L at the end of its steel, the such as 09MnREL, 06TiL 08TiL, 10TiL 09SiVL 16MnL 16MnREL.