we use our products seamless steel tubes or hot roller tube s355=fe52, sizes 76,1x8 and 88,9x10 both about 3000meters is year and rectangular tubes s355=fe52 sizes 200x100x8 about 1500meters in year and 100x200x4 about 800meters in year. cold draw or hot roller.lenght about 10-12meters is best. din example en10210 or en10297. i hope, that yoy inform us very soon