We are Riddhi Siddhi Impex, an ISO 9001, ISO 14001, and ISO 45001-certified Mumbai-based super duplex steel foils manufacturer and supplier established in 2002. Our precision linesslit solution annealed coil down to 0.03 mm against ASTM A240 / ASME SA-240. Two grades cover the whole range. A supplying capacity of 400 to 500 tonnes per month and dispatch within 4 to 5 days keeps gasket and instrumentation schedules on track.
Super duplex steel foils are thin-gauge flat products flat-rolled from super duplex stainless steel, a family whose microstructure divides into roughly equal halves of austenite and ferrite. Chromium near 25%, molybdenum between 3 and 5%, and a deliberate nitrogen addition push the pitting resistance equivalent number (PREN) above 40, the threshold that defines the super duplex class. A gasket winding, diaphragm, or sensing element survives hot chloride media that pit 316L, and because yield strength runs about double that of austenitic stainless, the part needs no added thickness to carry its load. One boundary applies: alpha-prime embrittlement, the 475 °C mechanism, gradually reduces toughness, so sustained duty belongs below roughly 250 °C.
As a reliable super duplex steel foil supplier, our Mumbai and Taloja warehouses hold solution annealed source coil in both grades, ready for slitting. Foil thickness is from 0.03 mm to 0.08 mm, with slit, deburred, or round edges finished to order. Every coil enters stock with mill documentation, so each foil order traces back to its original heat. ASTM A240 tabulates mechanical minimums for standard sheet and strip gauges; on foil below about 0.08 mm we report those values as indicative rather than guaranteed to the standard. Technical data sheets accompany dispatches on request, so specifiers can check chemistry before the material reaches their line.
We manufacture super duplex SS foils in 2 grades, UNS S32750 and UNS S32760, both held as ready stock in the solution annealed condition.
This high-strength, premium-grade foil offers exceptional corrosion resistance, making it the top choice for demanding offshore instrumentation.
View gradeAlloyed with tungsten and copper, this specialised foil resists hot seawater corrosion while maintaining excellent formability.
View gradeWe slit super duplex steel foils in 3 standard finishes; the gauge decides which applies. Requirements outside this list are quoted on a case-by-case basis.
BA
Annealing under a protective atmosphere keeps the foil surface bright and free of oxide. Instrument diaphragms and gauge foils normally call for BA.
2B
Cold rolling followed by annealing and pickling gives 2B its smooth, semi-reflective face. It's the default finish for general fabrication foil.
Matte
A low-gloss matte face arrives under a peelable PVC film. The film protects thin foil through transit and forming, then strips away cleanly at installation.
3 industrial sectors account for most of the SDSS foils leaving our lines. Chloride concentration and operating temperature at the point of use decide the grade.
Spiral wound gasket windings, instrument diaphragms, and subsea sensing elements rely on Super Duplex S32750 Foils through produced water and seawater injection duty. Where cathodic protection or hot crevice conditions make the environment harsher, platform engineers step up to S32760 foil.
Reactor seal foils and heat exchanger gaskets face mixed acids and hot chlorides on every campaign. Super Duplex S32760 Foils take the most aggressive streams because copper and tungsten slow both acid and crevice attack. For chloride-bearing process lines without acid exposure, S32750 stays the standard pick.
Reverse osmosis trains circulate warm brine around the clock, and Super Duplex S32750 Foils last for years there in sealing and spacing duty. Plant maintenance teams keep slit foil widths on hand for scheduled membrane and pump overhauls. Marine hardware builders form S32760 foil into sealing washers and locking elements for permanent seawater contact.
Traceable paperwork travels with every foil consignment. Riddhi Siddhi Impex holds three ISO certifications alongside heat-level mill traceability.
Each dispatch carries an EN 10204 Type 3.1 mill test certificate traced to the original heat. Type 3.2 certification with third-party witness is arranged on request.
Our ISO 9001:2015 certification covers the quality management system across slitting, inspection, and dispatch. Width and gauge checks are logged against each order before packing.
Environmental management runs under ISO 14001:2015, from coil storage through processing scrap handling.
ISO 45001:2018 governs occupational health and safety across our warehouse and foil production lines.
Flat-rolled stainless product falls under HS heading 7219 at widths of 600 mm or more and 7220 below that width. Foil slit to narrow widths almost always ships under 7220. Ask your customs broker to confirm the final subheading.
Riddhi Siddhi Impex has manufactured and stocked super duplex SS foils in Mumbai since 2002, supplying buyers across India and abroad. Call or WhatsApp our team and you'll have a quote within 24 hours.
