ASTM A106 is the black Carbon Steel Pipe for high-temperature, high-pressure service of Seamless Pipe in three grades A, B, and C of varying strength. ASTM/ASME A-106/SA-106 grade seamless pipes is one of our most widely used grade of carbon steel and is readily available ex-stock for all standard thicknesses up to SCH160. NPS 1-1/2 and under may be either hot finished or cold drawn. NPS 2 and larger shall be hot finished unless otherwise specified. Surface finish standards are outlined in the specification.Grades A and B are obtainable in most sizes and schedule numbers, Grade B permits higher carbon and manganese contents than Grade A. The A106 Grade B supplied by ASTM Seamless Pipes has a maximum carbon content of 0.23%.