Stainless steel
Stainless steels have a long history of application in contact with water due to their excellent corrosion resistance. Applications include a range of conditions from plumbing, potable and waste water treatment to desalination. Types 304 and 316 stainless steels are standard materials of construction in contact with water. However, with increasing chloride contents higher alloyed stainless steels such as Type 2205 and super austenitic and super duplex stainless steels are utilized.
Machinability
Stainless steels have poor machinability compared to regular carbon steel because they are tougher, gummier and tend to work harden very rapidly. Slightly hardening the steel may decrease its gumminess and make it easier to cut. AISI grades 303 and 416 are easier to machine because of the addition of sulphur and phosphorus.