Full threaded stud bolts in duplex stainless steel UNS S31803 (2205) supplied to ASTM A1082 / A1082M for high strength bolting in chloride-bearing and mildly sour service. Supplied with matched duplex heavy hex nuts where required. The ferritic-austenitic microstructure delivers roughly twice the yield strength of 316 stainless together with markedly better resistance to chloride stress corrosion cracking and pitting.

• Chloride SCC resistance: PREN≈34, suited to chloride-bearing process streams, cooling water and coastal atmospheres where 316L is prone to cracking.
• Higher strength, smaller bolts: 450 MPa minimum yield allows reduced bolt diameter and flange bolt circle compared with A4-70 / B8M bolting.
• Stress corrosion and erosion resistance: Resists pitting, crevice corrosion and erosion-corrosion in high flow seawater and brines.
• Balanced ferrite/austenite structure: Solution annealed and water quenched, ferrite content controlled at 35-55% for consistent toughness.

• Bar stock verified by optical emission spectrometry
• Solution annealing with water quenching, ferrite content checked per ASTM A923
• Microstructure tested for intermetallic phases (ASTM A923 Method A/B/C) as required
• Tensile testing per lot (ASTM A962/A370); hardness tested on bar material — every mill-treated length 2 in. and over, 10% sampling for smaller sizes; nut proof-load and cross-sectional hardness testing available on request (Supplementary S5/S6)
• ASTM G48 Method A pitting corrosion test available on request
• Dye penetrant and Go / No-Go thread gauging

Seawater cooling systems, desalination plants, offshore platform pipework, chemical tanker manifolds, pulp and paper bleaching lines, flue gas desulphurisation, heat exchanger flanges and coastal structural bolting.

Studs and nuts supplied as matched sets, interleaved and strapped in cartons, on plywood pallets or in crates. Neutral or customer-branded marking available. 60 tons monthly capacity for duplex grades, 15-25 days lead time.

Tell us your flange size, pressure class and expected service medium — we will confirm whether 2205 or a super duplex grade fits better and quote within one working day.