The seamless steel tube for special-purpose petroleum: Products such as API 5CT, 5L, etc.. Representative steel: 37Mn5, 27SiMn, 45Mn2, 15CrMo, 12CrMov, 42MnMo7, 40Cr, 10~45#, etc. The fuel takes coal as the core. Main supplier for tube blank is Tianjin Special Co., Ltd.