ASTM A53 Standard
This specification 2 covers seamless and welded black and hot-dipped galvanized steel pipe in NPS 1 ? 8 to NPS 26 [DN 6 to DN 650] (Note 1), inclusive, with nominal wall thickness (Note 2) as given in Table X2.2 and Table X2.3. It shall be permissible to furnish pipe having other dimensions (Note 2) provided such pipe complies with all other requirements of this specification.
Abstract from ASTM A53 Standard.