We are Riddhi Siddhi Impex, an ISO 9001, ISO 14001, and ISO 45001-certified Duplex Steel Foils manufacturer and supplier working from Mumbai since 2002. We precision-slit duplex stainless steel foil to ASTM and ASME standards. Ready stock, 400 to 500 tonnes of monthly supplying capacity, and dispatch within 4 to 5 days, keep fabrication programmes moving. We also provide EN 10204 Type 3.1 / 3.2 mill test certificates on request.
Duplex steel foils are thin, cold-rolled flat products made from stainless grades that hold austenite and ferrite in a near 50/50 balance. That two-phase structure delivers close to twice the strength of common austenitic stainless steels along with strong resistance to chloride pitting and stress corrosion cracking. Fabricators blank the foil into sealing elements, form it into heat exchanger internals, and slit it for instrumentation parts where a thin section must carry a real load in a corrosive stream.
As a reliable duplex steel foil supplier, our lines process duplex foil from 0.03 mm right up to 0.08 mm, supplied in the solution-annealed condition per ASTM A240. Every source coil reaches the slitter from a reputed primary mill with heat-traceable documentation already in hand. Coil inner diameters run 150 mm to 610 mm, and outer diameters reach 1800 mm, sized to suit your decoiler, while edges ship slit, mill, deburred, or round as ordered. Width is held to ±0.1 mm.
We supply precision-rolled Duplex 2205 foils directly from our warehouse to meet your high-strength, thin-gauge industrial engineering and manufacturing requirements.
We finish duplex steel foil in two ways; the end use decides which surface leaves our lines.
BA
A protective-atmosphere anneal keeps the surface bright and free of oxide scale. Instrumentation and cleanroom buyers specify it where cleanliness governs.
2B
Cold rolling, annealing, and pickling produce the smooth, mildly reflective 2B surface. It remains the default choice for gasket blanking and general press work.
3 sectors account for most of the duplex foil dispatched from Mumbai and Taloja, and each one buys the grade for its mix of chloride resistance and strength in thin section.
Process plants order Duplex 2205 foil for gasket blanks, diaphragms, and lining work in warm chloride streams. Austenitic stainless cracks under chloride stress in these conditions. The two-phase grade keeps working, and its extra strength lets designers thin the section without surrendering safety margin.
Offshore platforms and gas processing skids push saline, sometimes sour, media through tight-clearance equipment. Precision-slit Duplex 2205 foil goes into shim packs, sealing components, and instrument protection parts that must shrug off pitting while carrying mechanical load at a gauge measured in hundredths of a millimetre.
Hot, concentrated brine is the defining test here. Desalination trains route it past heat recovery elements and pump seals, and Duplex 2205 foil survives that high-chloride exposure because its nitrogen-strengthened chemistry holds off pitting long after standard stainless gives out in the same duty.
Traceability runs from mill heat to delivered coil. Riddhi Siddhi Impex pairs three ISO certifications with document-backed material control.
An EN 10204 Type 3.1 mill test certificate accompanies each duplex foil coil, tied to its heat number. We arrange Type 3.2 certification on request.
ISO 9001:2015 certifies the quality management system controlling our slitting, inspection, and dispatch operations.
Environmental practice across storage and material processing follows our ISO 14001:2015 certification.
ISO 45001:2018 covers occupational health and workplace safety on the slitting floor and in the warehouse.
Duplex is a stainless steel, so duplex steel foils move under HS heading 7220 when the flat-rolled width sits below 600 mm and 7219 at or above it. They never ship under the nickel heading 7506. Ask your customs broker to settle the final subheading.
Yes, Duplex foils stay on the shelf at our Mumbai warehouse throughout the year. Standard orders leave in 4 to 5 days, while urgent requirements are dispatched in 2 to 3.
Yes. Our slitting lines slit widths from 3 mm through 2000 mm in thicknesses down to 0.03 mm, keeping the width inside ±0.1 mm.
Riddhi Siddhi Impex manufactures duplex steel foils in Mumbai and supplies buyers across India and overseas, a business we have run since 2002. Phone or WhatsApp our team, and a quote will reach you within 24 hours.
