supply of 20nb heavy duty seamless pipe etc. , tube steel seamless heavy grade nominal bore 20 mm black plain ends to is- 1239 part1/ 2004.is:1239 (part 1):2004, amendment no.4 june 2010 ( pertains to mild steel) table 5 and plain ends. outside diameter ( minimum 26.5 mm and maximum 27.3 mm), wall t hickness 3.20 mm,nominal mass of steel tubes ( plain end) 1.870 kg/ mtr + 10%. lenth 06 m trs. material should be heavy duty seamless pipe, black. conditions:- totally rust free from inside & outside, fitted with protective cap at open ends. [ warranty period: 30 mon hs after the date of delivery ] [quantity tolerance (+/-): 5 %age , item category : normal , total po value variation permitt ed: max 8 lacs ] ]