UKEG also makes its ranges of profiles in stainless steel AISI 304 and 316L. The former has an 18% chrome content, with much better corrosion resistance with respect to the steel normally used in building. However it is less ductile and has a lower ultimate strength, and is sensitive to attack by sodium chloride, hydrochloric acid and sulphuric acid, which could cause oxidation and compromise the appearance and hygiene and functional aspects. AISI 316L contains a slightly lower amount of carbon, with more nickel and molybdenum, which help increase resistance to corrosive substances and guarantee total anti-rust defence. The yield limits this material achieves are very high (21÷42 against 17÷35 Kg/mm2), with equal elastic modulus and ultimate strength. This means that AISI 316L is by far the stainless steel that is technically and quality wise the best for outdoor frames. Hence the UKEG INOX PT was conceived, AISI 316L steel that guarantees quality, non-deformability in time and improved weldability.