... . The pipe end is plain or thread. And the connection are welding ends, coupling, bell and spigot .The grades are A,B,X42 ... ,X52,X56,X60,X65,X70,X80.The workmanship is ERW,SSAW and LSAW ... X52,X56,X60,X65,X70,X80TypeSeamless, weldingEndPlain, bevelConnectionWelding ends, coupling, bell and spigotWorkmanshipERW,SSAW,LSAW oil carbon steel seamless linepipe