The austenitic steel with designation 1.4404 contains molybdenum in addition to chromium and nickel. The difference against 1.4301/1.4307 apart from the presence of molybdenum is that the nickel content is greater. This type of stainless steel is often referred to as acid resistant which is to some degree a misnomer since the material resists attack only by weak acids. 1.4404 has low carbon content which means that it can be welded without risking impairment of corrosion resistance in the vicinity of the weld. In terms of strength, 1.4404 is more or less equivalent to the lower alloyed grades 1.4301/1.4307.
Flat formats of 1.4404 are standardised in EN 10088-2. This standard covers hot-finished strip with thicknesses up to and including 13.5 mm.
The presence of molybdenum along with chromium renders 1.4404 resistant to corrosion in weak acids and water containing chlorides so long as the chloride concentration is not too high; an example of an environment where the steel works well is salt-laden coastal atmosphere. The material is also a common choice for equipment in professional kitchens and for large-scale food processing.
The formability of hot-finished sheets of 1.4404 is in most cold-forming operations excellent and often equivalent to that of hot-rolled carbon steel. In addition, weldability is very good and there are seldom any issues in fabrication of welded structures.
The surface finish of hot-finished sheet in 1.4404 as stocked is 1D (annealed and with surface oxide removed by pickling).