① This standard has stipulated that brand No. with “A” can only be ordered as extremely high quality steel while other brand should be ordered as high quality steel.
② According to the requirements of the needer, goods can be ordered according to high quality steel (without “A”) or extremely high quality steel (all brand No.s). “A” or “E” should be added to the brand No (“A” should be crossed out as for those with “A” already). Once the needer raises any other requirements aimed at the chemical component of brand No., goods can be ordered according to special requirements.
③ The unified numeral code should be listed according to the GB/T 17616 stipulations. The last number of high quality steel should be “2”; senior high quality steel (“A” steel) should be “3”; extremely high quality steel (“E” steel) should be “6”.