supply of 15mm galvanized steel tubes medium grade is:1239 part -i 2004 both ends screwed one end with socket and other end with plastic thread protector, random length of 4 to 7 meters continuously welded electric resistant weld (erw), high frequency induction welded (hfiw), hot finished welded (hfw) light coatedisimark and socket also to be isimarked confirming to is: 1239 (part- ii)/2011. , 15mm galvanized steel tubes medium grade is:1239 part -i 2004 both ends screwed o ne end with socket and other end with plastic thread protector, random length of 4 to 7 meters contin uously welded electric resistant weld (erw), high frequency induction welded (hfiw), hot finished wel ded (hfw) light coatedisimark and socket also to be isimarked confirming to is: 1239 (part- ii)/201 1. [ warranty period: 30 months after the date of delivery ] ]