Ferritic/martensitic stainless (409/410/430/420), chromium-based and nickel-free — magnetic. Segregated by chrome content for value.

Trade Classification: 400-series Ferritic and Martensitic Stainless Scrap

Grade Composition and Specification

The 400-series stainless steels include ferritic (non-hardenable, magnetic, lower cost) and martensitic (hardenable, magnetic, higher strength) grades, all characterised by chromium as the primary alloying element without the nickel addition that defines austenitic grades. Common grades include: 409 (10.5–11.75% Cr, used for automotive exhaust systems), 410 (11.5–13.5% Cr, general-purpose martensitic), 430 (16–18% Cr, the standard ferritic grade used in automotive trim, appliance finishes, and flatware), 420 (martensitic, cutlery grade), and 441/439 (modified ferritics for automotive exhaust systems). The absence of nickel makes 400-series significantly less expensive than 300-series (no nickel cost), but also means that 400-series scrap cannot be used directly as a nickel source in 300-series production without nickel addition. 400-series scrap is magnetic (responds to a magnet), which is a key physical sorting characteristic distinguishing it from austenitic 300- and 200-series scrap (which are non-magnetic in the annealed condition). This magnetic property allows initial gross-level sorting of 400-series from other stainless grades using magnetic separation equipment.

Processing Challenges

The primary processing challenge for 400-series scrap is correct grade segregation — distinguishing 409 (low chrome, automotive exhaust) from 430 (higher chrome, trim and appliances) and from 410/420 (martensitic, cutlery and tooling) is commercially important because chrome content varies significantly (10.5% vs. 16–18%) and affects the value-in-use for secondary melting. Mixed 400-series lots must be assayed to determine average chromium content for pricing. 400-series scrap also has a lower residual value than 300-series (no nickel premium) and must be traded accordingly.

Who Uses SS 400 Series Scrap

Stainless steel producers making 400-series flat products (automotive trim coil, appliance finish coil, kitchenware sheet) and long products (cutlery bar, engineering bar) are the primary consumers. Automotive exhaust system manufacturers — a significant sector in India given the large two-wheeler and passenger car production base — generate large volumes of 409-grade stainless tube and pressed parts that flow back into the 409-grade scrap market upon end-of-life. Indian stainless producers with ferritic production capability (Jindal Stainless, Bahru Stainless for some grades) consume 400-series scrap in their ferritic heat production. Stainless cutlery and kitchenware manufacturers using martensitic 420 or ferritic 430 may melt trim scrap in-house or sell it to secondary stainless melters.