ASTM B167 UNS N06601 Inconel 601 Nickel Alloy Seamless Tube Solution Annealed Heat Exchanger Tube This page covers the seamless tube we cold-draw from UNS N06601 (Alloy 601 / W.Nr. 2.4851), the alumina-forming nickel-chromium-iron grade that buyers specify after 304H, 309S, 310S or Alloy 600 tubes have already failed by external scale spalling, wall thinning or creep sag in the 900–1150 °C band. The tube is manufactured to ASTM B167 / ASME SB167 in the cold-drawn, solution