... : 1.5752, 1.7218, 1.7220, 1.7225, 1.5805, 1.6571, 1.6511, 1.7131, 1.7016, 1.7033, 1.7035, 1.7177, 1.3505, 1.8159, 1.6523, 1.6526, 1.7103, 1.7108, 1.8509, 1.0722DIN ... Special Steel, Beiman Special Steel, Dalian Special Steel, Xining Special Steel, Xingcheng Steel, Wuyang Steel and Benxi Iron and Steel, and summed up valuable experience of domestic special steel ...