Surface Treatments
Certifications
- ISO 9001:2015
- NORSOK M-650
- NACE MR0175
- ISO 15156-3
- PED 2014/68/EC
- EN 10204 type 3.2
- AD 2000 W2/W7/W10
Ferralium 255 Round Bar (UNS S32550), ASTM A479
Ferralium 255 round bar (UNS S32550 / EN 1.4507 / X2CrNiMoCuN25-6-3) is the most-specified product form for super duplex bolting, machined components, and downstream forging stock. Manufactured by TorqBolt at Mumbai & Rajkot, India to ASTM A479 (primary) or ASTM A276 (alternative), supplied solution-annealed at 1100 °C with water quench. Per-heat Mill Test Certificate to EN 10204 type 3.2 with chemistry, mechanical properties, ferrite content per ASTM E562, and PREN calculation.
Size Range & Tolerances
| Diameter range | Length | Form / finish | Tolerance |
|---|---|---|---|
| 6 mm – 50 mm | up to 6 m | Cold-finished / peeled / centreless-ground | h9 / h10 (ISO 286) |
| 50 mm – 200 mm | up to 6 m | Hot-rolled / cold-finished | h11 / k12 |
| 200 mm – 400 mm | up to 4 m | Hot-rolled / forged | k12 / k13 |
| 400 mm – 600 mm | cut to length | Forged bar (ASTM A182) | k13 / k14 |
Chemistry & Properties
Per ASTM A479 / UNS S32550: Cr 24.0–27.0%, Ni 4.5–6.5%, Mo 2.9–3.9%, Cu 1.5–2.5%, N 0.10–0.25%, balance Fe. Yield ≥ 550 MPa, tensile ≥ 760 MPa, elongation ≥ 15%, hardness ≤ 32 HRC (NACE MR0175 limit), Charpy at −46 °C ≥ 45 J (NORSOK M-630), PREN ≥ 40, CPT ≥ 35 °C per ASTM G48 method A. Full chemistry / mechanical reference on the Ferralium 255 grade page.
Typical End-Use Applications
- Machined component blanks, Ferralium 255 hex bolts, stud bolts, hex nuts (B16.5 flange bolting)
- Pump shafts and impellers for seawater service
- Downhole tool components for oil & gas (NACE MR0175 sour service)
- Subsea X-mas tree and wellhead internals (NORSOK M-650 qualified)
- Heat exchanger tube sheets and end caps
- Forging stock for flanges and fittings (ASTM A182)
Specification Compliance
- ASTM A479, primary bar specification
- ASTM A276, bars and shapes (alternative)
- EN 10088-3 (1.4507), European long products
- EN 10272, bar for pressure purposes
- NORSOK M-650 QTR, manufacturer qualification per MDS D55
- NACE MR0175 / ISO 15156-3, sour-service compliance per heat
- EN 10204 type 3.2, per-heat Mill Test Certificate
Ordering Information
Specify: diameter (mm or inch); length (mm or m); finish (hot-rolled / cold-finished / peeled / centreless-ground / forged); spec (ASTM A479 / A276 or EN 10088-3); supplementary requirements (NORSOK M-650 QTR, NACE MR0175 compliance, intergranular corrosion test per ASTM A923, ferrite-content range, CPT ≥ 35 °C per ASTM G48). Contact info@torqbolt.com or +91-22-66157017 for quotation and lead time.
Need Ferralium 255 round bar? Email info@torqbolt.com or WhatsApp +91-22-66157017 with form, dimensions, quantity, ASTM/EN spec, MTC level (3.1 / 3.2). NACE MR0175 sour-service stamp on every heat. NORSOK M-650 QTR on request. Per-heat EN 10204 type 3.2 MTC included with every consignment.
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