316L Flange is an improved version of 304 due to the addition of molybdenum and a slightly higher nickel content. The resultant composition of 316 gives the steel improved corrosion resistance in many aggressive environments.

The molybdenum makes the steel more resistant to pitting and crevice corrosion in chloride-contaminated media, seawater, and to acetic acid vapors. The lower rate of general corrosion in mildly corrosive environments gives the steel good atmospheric corrosion resistance in polluted marine atmospheres.

316 offers higher strength and better creep resistance at higher temperatures than 304. 316 also provides excellent mechanical and corrosion properties at sub-zero temperatures. When there is a danger of corrosion in the heat-affected zones of weldments, the lower-carbon variety 316L should be used.