Starship's body is made from welded SAE 304L stainless steel rings, 9 m (30 ft) diameter, 3.97 mm (0.156 in) thick, 1.8 m (5 ft 11 in) tall.http://www.matweb.com/search/datasheet_print.aspx... Austenitic Cr-Ni stainless steel. Better corrosion resistance than Type 302. High ductility, excellent drawing, forming, and spinning properties. Essentially non-magnetic, becomes slightly magnetic when cold worked. Low carbon content means less carbide precipitation in the heat-affected zone during welding and a lower susceptibility to intergranular corrosion. Applications include beer barrels, bellows, chemical equipment, coal hopper linings, cooling coils, cryogenic vessels, dairy equipment, evaporators, feedwater tubing, flexible metal hose, food processing equipment, hypodermic needles, nuclear vessels, oil well filter screens, refrigeration equipment, paper industry, pressure vessels, sanitary fittings, valves, shipping drums, spinning, still tubes, textile dyeing equipment, tubing.