... ", 1" 6 -40- 101 DEG C temperature operation of seamless steel tubes for ASTM A333, GR.A, GR.1, GR. 6 grade ... .7-711.2mm In 7the German standard DIN2448 /1629 seamless steel tubes, steel grade: St37, St44, St52, specifications: 1/ 4" -28", 13.7 ... , 20, 35# # #, 45, #, specifications: 6-720* 1-70mm 10 Seamless steel pipes conveying fluid GB / T8163-1999, grades: 10,20, # #, specifications:6 ...