Special and Super Austenitic Stainless Steel Fittings Supplier, Stockist and Exporter

Aurico Alloys LLP supplies special stainless steel fittings from ready stock in Mumbai to customers across India and in more than 40 export markets. Fittings carry the same corrosion duty as the pipe they join but see higher stress concentration at every change of direction, so grade traceability and wall thickness at the extrados matter more here than anywhere else in a piping system.

Special Stainless Steel covers high-alloy austenitic stainless grades bridging the gap between 316L and nickel alloys. Fittings are supplied with heat-number traceability and can be bevelled, tacked or pre-fabricated into spools on request.

Sizes and Specifications

Special Stainless Steel Fittings - standard supply range
Size rangeButt-weld fittings 1/2" to 48" NB in Sch 5S to Sch XXS; forged socket-weld and threaded fittings 1/8" to 4" NB in 3000#, 6000# and 9000# classes.
Types and finishesElbows (45° and 90°, long and short radius), tees (equal and reducing), reducers (concentric and eccentric), caps, stub ends, couplings, unions, plugs and bushings.
SpecificationsASME B16.9 and B16.28 for butt-weld, ASME B16.11 for forged fittings, with material to ASTM B366 / A815 / B363 as applicable.
CertificationEN 10204 3.1 mill test certificate; 3.2 and third-party inspection on request
OriginIndian and imported mills, fully traceable by heat number

Specifications by Grade – Fittings

A specification is written for a product form. The standards below are the ones that cover fittings; the plate, bar and tube specifications for these grades are different documents and are listed on their own pages.

GradeUNSFittings specification
904LN08904ASTM B366
254 SMOS31254ASTM A403
AL-6XNN08367ASTM B366
Alloy 20N08020ASTM B366
Alloy 28N08028ASTM A403

Grades and International Equivalents

Special Stainless Steel grades stocked, with UNS and Werkstoff equivalents
GradeUNSWerkstoff (W.Nr.)
Alloy 20 (Carpenter 20)N080202.4660
Alloy 28 (Sanicro 28)N080281.4563
Alloy 31N080311.4562
Alloy 904LN089041.4539
254 SMOS312541.4547
AL-6XNN08367
Alloy 926N089261.4529
AM-350S35000

Chemical Composition

These grades carry 20-27% chromium, 18-31% nickel and 4-7% molybdenum, with copper added in Alloy 20 and 904L for sulphuric acid service and nitrogen in 254 SMO and AL-6XN to lift pitting resistance.

Mechanical and Physical Properties

Typical tensile strength is 490-690 MPa. PREN values of 43 and above for 254 SMO and AL-6XN give pitting resistance close to nickel alloys at appreciably lower cost.

Industry Applications

How fittings is used

Fittings are factory-made wrought components to ASTM B366, dimensioned to ASME B16.9 for butt-weld and ASME B16.11 for socket-weld. They are the 45, 90 and 180 degree elbows, tees, reducers, caps and lap-joint stub ends that change direction, branch or change bore in a process line, and they are specified to match the pipe they join in both alloy and schedule so the weld and the corrosion behaviour stay continuous.

Where special stainless steel fittings is specified
IndustryTypical use
Chemical processingSulphuric and phosphoric acid plant, pickling lines and heat exchangers.
Pollution controlFlue-gas desulphurisation absorbers and scrubber internals.
DesalinationSeawater heat exchangers and high-chloride service.
Pulp and paperBleach plant equipment and chloride-bearing white liquor systems.
Oil and gasProduced-water handling and offshore process equipment.

Testing and Certification

Every consignment ships with an EN 10204 3.1 mill test certificate stating heat number, chemical analysis and mechanical properties. Depending on grade and specification we can supply positive material identification (PMI), ultrasonic and dye-penetrant testing, intergranular corrosion testing to ASTM A262 or G28, hydrostatic testing, and third-party inspection release notes from Lloyd's Register, Bureau Veritas, SGS or TUV.

Aurico Alloys LLP operates an ISO 9001:2015 quality management system. Material for sour service can be supplied certified to NACE MR0175 / ISO 15156 where the grade permits.

Request a Quotation

Send your grade, size, quantity and specification and we will respond with price and lead time, usually the same working day. Call +91 7977 88 6611 or email info@auricoalloys.com.

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