supply of 1.ms square tubes of size 45 x 45 x 2.6 mm to is specn no. is:-4923 / 1997 with latest amendment no.1 hf shs gr. yst-240 with plain carbon steel 2.ms square tube size 20 x 20 x 1.6mm, ms square tube size 20 x 20 x 1.6mm to specn is :4923-97 with amend no.1 to 4, hf shs / grade-yst 240 with plain carbon steel with minimum carbon of 0.15 percent ( or ) steel with equivalent carbon content of maximum 0.39 percent in spectfic length of 6.14mts in excess length in multiples of 0.77 mts up to a max length of 7.68mts. the tube shall be oiled externally with rust preventive oil. [ warranty period: 30 months after the date of delivery ] sr section engineer, cb, carriage tamil nadu 7840.00 metre , ms square tubes of size 45 x 45 x 2.6 mm to is specn no. is:-4923 / 1997 with latest amendment no.1 hf shs gr. yst-240 with plain carbon steel with minimum carbon of 0.15% ( or ) steel with equivalent carbon content of maximum 0.39% in specific length of 6.14 meters. [ warranty period: 30 months after the date of delivery ] sr section engineer, cb, carriage tamil nadu 3500.00 metre