GB 312 Stainless Steel Flat Bar 1. grade:200 , 300 , 400 ... . size: 3mm - 12mm x 25mm - 120mm 3. ISO , BV , GSG GB 312 Stainless Steel Flat Bar 1. grade: 201 , 202 , 301 ... . size: 3mm - 12mm x 25mm - 120mm3. standard: ASTM , AISI , JIS , GB , DIN ,EN4.surface: bright , pickled , black5..ISO , GSG , BV . We ...