Why PPE only uses 304 stainless steel and will never use 409 stainless for any PPE products.
304 stainless steel is the highest-quality stainless steel in commercial automotive use. 304 stainless steel is very tough and highly corrosion-resistant, with a 20% chromium and 10% nickel alloy content. 304 stainless steel is also nonmagnetic due to its low ferrous metal content, therefore not attracted to magnetic fields.
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409 stainless steel is used in most stainless steel exhaust systems because of its significantly lower cost. With a lower chromium content (10-12%) and nickel alloy content at only .05% it is more likely to rust, especially in cold and wet climates. 409 stainless steel also contains a higher ferrous metal content causing it to be attracted to magnetic fields.
