At room temperature, yes. At the range of temperatures this needs to operate at, stainless is actually lighter for the required strength. Keep in mind that thi

At room temperature, yes. At the range of temperatures this needs to operate at, stainless is actually lighter for the required strength. Keep in mind that this is a tank for cryogenic propellants (almost-solid liquid oxygen and methane), that needs to survive atmospheric re-entry from interplanetary speeds, so it needs to be strong in temperatures around -200°C to +400°C.