supply of brass tubes and conversion of old brass tube into new brass tube to various co-operative and corporation sugar mills in uttarakhand in the year 2023-24 , new seamless solid drawn 70:30 alloy brass tubes heat treated and guaranteed against dezincification and season cracking, tested to 1000 psi with ends suitable for expansion in tube plate, conforming to is:407-81, alloy-1, with test certificate. annealed condition having tolerance as per is: 5493/81 , size upto 2” dia , size above 2” dia , supply ofnew brass tubes (specifications same as mentioned above at s.no.1) on conversion basis , size upto 2” dia , size above 2” dia , current price of copper (cu) , current price of zinc (zn)