When should a 316 Stainless Steel be selected over 302 Stainless Steel for a spiral retaining ring despite the lower tensile strength?

While 302 Stainless Steel offers a higher tensile strength due to its higher carbon content and work-hardening rate, 316 Stainless Steel is preferred in environments where molybdenum is required to resist pitting and crevice corrosion. 316 contains 2-3% molybdenum, which significantly improves resistance to chlorides (e.g., seawater, de-icing salts). In medical or chemical processing applications, the risk of Stress Corrosion Cracking (SCC) is higher with 302. Therefore, if the application involves immersion in saline solutions or harsh chemicals, 316 is the correct metallurgical choice. The engineer must compensate for the roughly 10-15% lower thrust capacity of 316 by either increasing the ring thickness or using a deeper groove.