We are Riddhi Siddhi Impex, an ISO 9001, ISO 14001, and ISO 45001-certified Mumbai-based Duplex Steel Coils supplier and stockist established in 2002. We stock hot rolled and cold rolled duplex coils to ASTM A240 / ASME SA-240 from established primary mills, slit on our own lines to any width from 3 mm to 2000 mm. Ready inventory, 400 to 500 tonnes of monthly supplying capacity, and dispatch in 4 to 5 days keep fabrication schedules intact.
Duplex steel coils are continuous flat-rolled lengths of austenitic-ferritic stainless steel wound after hot or cold rolling. The microstructure splits close to half and half between the two phases, and each contributes what the other lacks. Ferrite supplies strength plus resistance to chloride stress corrosion cracking, while austenite brings toughness and weldability. Together, they let a duplex coil carry loads that would need a far thicker section in 304 or 316, so fabricators trim weight and material cost out of the same design. Chloride-laden water that pits standard austenitic strip within months leaves a duplex surface largely untouched.
As a reputable duplex steel coils stockist, we maintain our slitting lines in our Mumbai warehouse. Cold-rolled stock begins at 0.03 mm; hot-rolled handles the thicker end, up to 5 mm. Coil ID spans 150 mm to 610 mm with OD reaching 1800 mm, which suits most decoiler setups without modification. Mill documentation travels with each full-width coil before it reaches the slitter, and material ships solution annealed, the condition ASTM A240 sets for duplex flat products. To secure a dependable duplex steel coil supply, order a complete source coil or have us slit it down to width; both start from one shelf.
We supply high-performance Duplex 2205 coils directly from our fully stocked warehouse to meet your critical industrial engineering and heavy manufacturing requirements.
We supply duplex stainless steel coils in 3 finishes; the rolling route determines which applies.
HR
Pickling strips mill scale from hot rolled coil and leaves a uniform matte face for heavy-gauge forming and structural parts.
2B
Annealing and pickling after cold rolling yield the smooth, faintly reflective 2B face. Most cold rolled duplex coil leaves our warehouse this way.
BA
A protective atmosphere during annealing keeps the cold rolled surface reflective, chosen where parts stay visible or need easy cleaning.
3 sectors widely use the duplex coil tonnage we slit and dispatch. Each one specifies Duplex 2205 where chlorides and mechanical load arrive together.
Process plants roll Duplex 2205 coil into reactor cladding, tank shells, and pressure vessel components, handling warm chloride media. The grade resists the chloride cracking that tears open 316 vessels, and its extra yield strength permits lighter builds. We keep slit widths ready for shutdown replacement windows.
Offshore topsides and subsea hardware run in seawater that occasionally turns sour. Operators form Duplex 2205 coil into separator internals, flowline components, and manifold parts that must resist seawater pitting while carrying structural load. Slit widths go straight onto roll formers, so fabrication yards skip one handling stage.
Hot, concentrated brine defines this duty. Desalination contractors fit Duplex 2205 coil into evaporator flash stages, heat recovery shells, and pump parts where the nitrogen-boosted chemistry holds pitting in check. Shipbuilders pull the same slit material for splash-zone sheathing and seawater piping supports that outlast austenitic alternatives.
Documented quality stands behind every duplex coil dispatch. Riddhi Siddhi Impex pairs three ISO certifications with mill-level traceability.
Every coil ships with an EN 10204 Type 3.1 certificate traceable to the originating mill heat. Type 3.2 comes on request.
Our ISO 9001:2015 certificate confirms the quality management system running through procurement, storage, and slitting.
ISO 14001:2015 covers our environmental responsibilities, spanning material storage, handling, and dispatch in the warehouse.
ISO 45001:2018 governs occupational health and safety across the warehouse and the slitting bay.
Duplex is a stainless steel, so flat-rolled duplex coils classify under HS heading 7219 at widths of 600 mm and above, and under 7220 below that. Your customs broker confirms the final subheading.
Yes, Duplex coils sit on the shelf in Mumbai throughout the year. Regular orders go out in 4 to 5 days, urgent ones in 2 to 3.
Yes. Any width from 3 mm to 2000 mm comes off our slitting lines at a ±0.1 mm tolerance. Coil ID options span 150 mm to 610 mm, and OD goes up to 1800 mm.
Riddhi Siddhi Impex has stocked duplex steel coils in Mumbai since 2002, serving buyers across India and overseas. Call or send a WhatsApp message, and a quote will reach you within 24 hours.
