The most rust-resistant grades of stainless steel have lower tensile strength and hardness, and work-harden in a way that makes forming them a bit more expensiv

The most rust-resistant grades of stainless steel have lower tensile strength and hardness, and work-harden in a way that makes forming them a bit more expensive. For example, your kitchen sink might be made out of 304 or 316 stainless steel - but your kitchen knives are more likely to use 440C which is less corrosion-resistant, but will hold an edge a lot better. It also helps that you're not whacking road salt into your kitchen sink at 70mph.