17-7 PH is a semi-austenitic precipitation-hardening stainless steel (chromium-nickel-aluminum alloy) designed for high strength, excellent fatigue performance, and good corrosion resistance (comparable to 304 stainless steel), with a maximum operating temperature of 600°F (316°C). Due to its minimal distortion during heat treatment and high strength, it is commonly used in aerospace, springs, washers, and bellows applications.

17-7 PH stainless steel spring wire is a high-strength precipitation-hardening (PH) alloy (UNS S17700) known for its excellent fatigue resistance, corrosion resistance similar to 302/304 stainless steel, and minimal distortion during heat treatment. It is widely used in aerospace applications for springs, rings, and fasteners, and can operate at temperatures up to 600°F (316°C).

EN 1.4401 is a European standard designation for austenitic stainless steel, widely known as AISI 316 or Grade 316, famous for its excellent corrosion resistance, especially in chloride environments, thanks to added molybdenum, making it crucial for marine, chemical, and food processing industries. It offers good mechanical properties, even at cryogenic temperatures, and good weldability.

1.4372 stainless steel (also known as AISI 201) is a low-nickel austenitic stainless steel with high strength, good ductility, and excellent work-hardening properties. It typically has a tensile strength exceeding 600 MPa and a yield strength exceeding 245 MPa.

The main difference between the two is that 1.4057 has higher strength and hardness after heat treatment, while 1.4301 exhibits better ductility and corrosion resistance under general usage conditions.

1.4301 is the European EN 10088​ designation, while AISI 304​ is the American ASTM/UNS​ designation. They represent the same basic austenitic stainless steel grade, with essentially identical chemistry and mechanical properties; the differences lie mainly in the standards' specified limits and testing methods.