ASTM A53 Gr.B seamless steel pipe includes black pipe and hot dipped galvanized pipe, the diameter of of ASTM A53 Gr.B seamless steel pipe range from 21.3 mm to 720 mm, and wall thickness range from 2mm to 120mm. A53 Gr.B seamless steel pipe is used for general purposes of steam, water, gas and air lines. 1) Standard: ASTM A53/A53M 2) Material: Gr.B Seamless pipe 3) OD: 21.3 ~ 720mm 4) wall thickness: 2 ~ 120mm 5) Length: 5m ~ 12m ASTM