1. Standard: ASTM A106/A53, GB/T 8162 2. Material: ASTM A106/A53 Gr B, 10, 20, 45, Q345 etc 3. Tolerance: by the standard 1. Standard: ASTM A106/A53, GB/T 8162 2. Material: ASTM A106/A53 Gr B, 10, 20, 45, Q345 etc3. Tolerance: by the standard 4. Size: OD: 89mm-325mm, can be manufactured by customer's requirement; WT: 4mm-60mm; Length: 6M~12M, length can be manufactured by customer requirement.5. ...