... 6" Schedule 40 ASTM A53 A106 Grade B Black Carbon Seamless Steel Pipe We ... 40 ASTM A53 A106 Grade B Black Carbon Seamless Steel Pipe is one of our main products, the following are ... A53 / ASTM A106/API 5L Steel Material and Grade: Grade A,Grade B,Grade C,X42,X52,X60,X6,X70,L245,L450 ... and after-production inspection for our products. We ensure that the products are produced,tested,and inspected strictly ...