We are Riddhi Siddhi Impex, an ISO 9001, ISO 14001, and ISO 45001-certified Mumbai-based super duplex steel strips manufacturer and supplier established in 2002. We slit strips in-house from mill-certified source coils to ASTM A240 / ASME SA-240, holding any width between 3 mm and 2000 mm. We hold ready solution-annealed stock, supply 400 to 500 tonnes per month, and dispatch within 4 to 5 days, so chloride-service projects stay on schedule.
Super duplex steel strips are flat-rolled lengths of duplex stainless steel with a microstructure of roughly half austenite and half ferrite. The two phases divide the work: ferrite supplies strength, austenite holds toughness and weldability. Around 25% chromium, 3 to 5% molybdenum, and a deliberate nitrogen addition lift the pitting resistance equivalent number, calculated as %Cr + 3.3(%Mo + 0.5%W) + 16%N, past 40. That PREN threshold separates super duplex from standard duplex grades such as 2205. Strip in this family resists pitting, crevice corrosion, and chloride stress corrosion cracking in seawater and brine that would attack 316L, and its yield strength runs roughly double that of common austenitic grades. One boundary applies: keep continuous service below about 300 °C, because alpha-prime embrittlement (the 475 °C mechanism) slowly reduces toughness above it.
Our Mumbai and Taloja warehouses hold solution-annealed super duplex stock ready for slitting. Cold rolled strip runs from 0.03 mm to 5 mm thick, wound on coil IDs of 150 mm to 610 mm with ODs up to 1800 mm. Each stainless steel coil brings its mill documentation into stock, and buyers choose slit, deburred, or round edge conditioning to suit their forming and assembly route. Technical data sheets accompany the material on request, so specifiers can verify chemistry and mechanicals before the coil reaches the slitter.
We process 2 super duplex strip grades. UNS S32750 and UNS S32760 both move from ready stock in Mumbai and Taloja.
This 25Cr grade offers high strength and premium corrosion resistance, making it a top choice for offshore buyers.
View gradeEnhanced with tungsten and copper, these durable strips provide superior crevice corrosion resistance while remaining highly weldable.
View gradeWe supply super duplex steel strips in 4 regular finishes. BA, 2B, Scotch-Brite and Matte surfaces are arranged on request for heavier gauges.
BA
Bright annealing under a protective atmosphere leaves a reflective, oxide-free surface that needs no further polishing before use.
2B
Most cold rolled super duplex strip ships as 2B: annealed, pickled, then lightly rolled to a smooth, semi-reflective face that suits general fabrication.
No. 4
A uniform brushed texture doesn't show handling marks on visible components. Fabricators specify it when appearance and grip both matter on the finished part.
Matte
A dull, non-reflective finish achieved by textured rolls. It eliminates glare and improves coating or lubricant adhesion during heavy fabrication.
Most super duplex stainless steel strips issued from our slitters serve 3 industrial sectors. The corrosion medium and the operating temperature decide the grade for each order.
Platforms and subsea systems consume slit super duplex strip in three main shapes: clamps and springs, banding, and instrumentation components. Super Duplex S32750 Strips handle produced water and seawater injection circuits, and sour wells accept the grade within its qualified hardness limits. Subsea banding in contact with cathodic protection systems often steps up to S32760.
Gasket windings face hot chlorides and mixed acids daily. Reactor internals and heat exchanger seal strips share the same exposure. Super Duplex S32760 Strips take the harshest of these streams, excelling where sulphuric acid dominates the process chemistry.
Reverse osmosis plants and brine concentrators run warm seawater around the clock. Super Duplex S32750 Strips form the screens, fastening bands, and spring elements that survive this duty for years without pitting. Plant maintenance teams keep slit widths on hand for scheduled membrane and pump overhauls.
Traceable paperwork accompanies every strip consignment, with heat numbers carried through from mother coil to slit width. Three ISO certifications stand behind our slitting and dispatch operations.
Each dispatch carries an EN 10204 Type 3.1 mill test certificate traced to the original heat. Type 3.2 certification is available on request.
Quality management from slitting through inspection to supply runs under our ISO 9001:2015 certification.
ISO 14001:2015 governs our environmental practices, from material storage through processing waste handling.
Occupational health and safety at the warehouse and slitting lines operates under ISO 45001:2018.
Flat-rolled stainless product 600 mm or wider falls under HS heading 7219, and narrower material under 7220. Since most custom-slit strip is under 600 mm, orders usually ship under 7220. Your customs broker should confirm the final subheading before export.
Yes. Any width from 3 mm to 2000 mm is slit to order, with width tolerance held at ±0.1 mm. Coil IDs span 150 mm to 610 mm, ODs reach 1800 mm, and edge conditioning is finished to your specification.
Riddhi Siddhi Impex has manufactured and stocked super duplex SS strips in Mumbai since 2002, serving buyers across India and abroad. Call or WhatsApp our team; you'll have a quote within 24 hours.
