... JIS,EN,TP304,321,316L.... Appliance:high quality electric element,heater O.D.:from 6mm to ... Standard2) Material of commonly used stainless steel:TP304,TP321,TP316L,TP309S,TP310;Material of other ... bright/annealing Note:Producing stainless steel welded pipes used for electric heating tubes for well over a dozen ... steel pipes/tubes by company bring no worry to the customers in terms of the quality ...