American Society for Testing and Materials (ASTM). Current edition approved Oct. 1, 2009. Published November 2009. Originally approved in 1931. Last previous edition approved in 2006 as A135/A135M – 06. 9 p. This specification covers two grades of electric-resistance-welded steel pipe in NPS 2 to NPS 30 [DN 50 to DN 750] inclusive, with nominal (average) wall thickness up to 0.500 in. [12.70 mm], inclusive, and in nominal sizes NPS 3⁄4 to NPS 5 [DN 20 to DN 125] inclusive with nominal (average) wall thickness 0.083 in. [2.11 mm] to 0.134 in. [3.40 mm], depending on size. Pipe having other dimensions (Note 1) may be furnished provided such pipe complies with all other requirements of this specification.