Hastelloy C276
Fasteners
UNS N10276
Hastelloy C276 — 16% Mo · Oxidising + Reducing Media
Hastelloy C276 (UNS N10276) contains 15–17% molybdenum — the highest Mo content in the commercial Ni-Cr-Mo alloy family — combined with 14.5–16.5% Cr and 3–4.5% W. This composition provides a unique capability: excellent resistance across both oxidising and reducing acid environments simultaneously. Where C-series Ni-Cr-Mo alloys and B-series Ni-Mo alloys each excel in their respective acid types, C276 covers both — making it the default specification for multipurpose chemical plants, mixed-media process equipment, and any bolted connection where process fluid varies or is not precisely defined.
Compared with the C276 product pages already on akbarfasteners.in: the C276 stud bolts page covers ASME B16.5 configurations, the C276 bolts page covers DIN hex bolt forms and the grade selection matrix, and the C276 washers page covers matched-material assembly. This page gives you the complete picture — all product forms available from Akbar Fasteners Pvt. Ltd. in UNS N10276 — linked to the detailed sub-pages for each form.
The ultra-low carbon (≤0.010%) prevents sensitisation at weld heat-affected zones. Tungsten (3–4.5%) enhances resistance to crevice corrosion and pitting specifically in reducing chloride environments. All C276 fasteners from Akbar Fasteners are manufactured from ASTM B574 certified bar, XRF PMI-verified before production, with matched hex nuts and C276 washers from the same heat available.
| Element | Min % | Max % | Typical |
|---|---|---|---|
| Nickel (Ni) | Balance | — | ~57% |
| Molybdenum (Mo) | 15.0 | 17.0 | ~16% |
| Chromium (Cr) | 14.5 | 16.5 | ~15.5% |
| Tungsten (W) | 3.0 | 4.5 | ~4% |
| Iron (Fe) | 4.0 | 7.0 | ~5.5% |
| Cobalt (Co) | — | 2.5 | — |
| Carbon (C) | — | 0.010 | — |
| Silicon (Si) | — | 0.08 | — |
| Vanadium (V) | — | 0.35 | — |
Hastelloy C276 Fasteners — All Product Forms
All product forms machined from ASTM B574 certified UNS N10276 solution-annealed bar, PMI-verified. Matched sets from same heat — one MTC, one PMI, one COC for the complete assembly.
C276 Stud Bolts
Fully threaded and double-end. Class 150–2500. M12–M100, lengths to 3,000mm. Primary C276 fastener for ASME B16.5 pressure flanges in mixed acid, offshore, and chemical plant service.
View Stud Bolts →C276 Hex Bolts
Full thread DIN 933, partial thread DIN 931, heavy hex ASME B18.2.3.6M, socket cap DIN 912. M6–M100. Chemical equipment covers, reactor body bolts, and mixed-media flanges.
View Hex Bolts →C276 Hex Nuts
Standard hex DIN 934, heavy hex ASME B18.2.2, coupling nuts DIN 6334. M6–M100. Matched material from same ASTM B574 certified heat as stud bolts — zero galvanic risk in mixed acid assemblies.
View Hex Nuts →C276 Washers
Plain flat DIN 125 A/B, spring helical DIN 127, and large OD DIN 9021. M5–M100. Same-heat as stud bolts — matched material eliminates galvanic corrosion at the nut bearing face in any mixed acid or chlorinated service.
View Washers →C276 Threaded Rods
Full thread DIN 975 and end-thread DIN 976. M6–M100, lengths to 3,000mm. Chemical plant hanger systems, equipment support tie-rods, and offshore structural rods in mixed acid splash zones.
View Threaded Rods →Socket Cap Screws
Hex socket cylindrical head for confined-access chemical equipment bolting. M4–M48. Chemical reactor internals, agitator baffle attachment, heat exchanger internal fixtures, and instrument flange bolting in mixed acid and chlorinated solvent service.
View Socket Screws →Matched Assembly Sets
Stud bolts + heavy hex nuts + washers from same certified UNS N10276 heat. One MTC, one PMI XRF report, one COC for the complete flange assembly — single vendor document package for EPC and TPI hold plan submission.
Request Matched Set →Custom / ASTM B574 Range
Non-standard diameters, inch UNC/UNF, left-hand thread, drawing-specific forms, and C276 alongside full ASTM B574 C-series range (C22, C4, C276). Send drawing or inquiry to sales@akbarfasteners.in.
View ASTM B574 Range →Hastelloy Grade Selection Matrix
All three grades are available from Akbar Fasteners Pvt. Ltd. in the same product forms. Use this matrix to identify the optimal grade for your corrosion environment — then click through to the relevant product page.
| Corrosion Environment | C276 (N10276) — This Page | C22 (N06022) | B3 (N10675) |
|---|---|---|---|
| Mixed / Variable / Unknown Acids | ✔ Best Choice | Limited range | Limited range |
| Oxidising Acids (HNO₃, HClO₄) | Good | ✔ Best Choice | Avoid |
| Oxidising Chloride / FGD Service | Good | ✔ Best Choice | Avoid |
| Reducing HCl (all concentrations) | Moderate | Poor | ✔ Best Choice |
| Dilute H₂SO₄ (reducing) | Good | Moderate | ✔ Best Choice |
| Chlorinated Solvents / Wet Cl₂ | ✔ Best Choice | Good | Avoid |
| Seawater (all temperatures) | Excellent | ✔ Excellent | Good |
| Phosphoric Acid (H₃PO₄) | ✔ Excellent | Good | Moderate |
| Organic Acids (acetic, formic) | ✔ Excellent | Good | Good |
| NACE H₂S Sour Service | ✔ Compliant | ✔ Compliant | Check hardness |
| Multipurpose / Campaign-Change | ✔ Best Choice | Limited | Limited |
Grade selection guidance: ASTM B574 Hastelloy Fasteners · Hastelloy C22 Stud Bolts · Hastelloy B3 Stud Bolts
Standards We Manufacture & Test To
Same quality system as our Hastelloy B3 stud bolts and complete alloy range. Full heat traceability from mill certificate to dispatch.
Industry Applications
Mixed or variable acid environments, multipurpose chemical plants, and any application where the broadest single-alloy coverage across both oxidising and reducing media is required.
Multipurpose Chemical Plant
campaign-change reactors
FGD Scrubbers
wet SO₂ + chloride service
Oil & Gas
chemical injection flanges
Offshore Platforms
FPSO mixed-media flanges
Pulp & Paper
bleach plant connections
Desalination
mixed media brine systems
Pharmaceutical
variable acid CIP flanges
Waste Treatment
mixed scrubber connections
Complete Documentation Package
Heat & Lot Traceable
Conformance
100% Lots Verified
Tensile · Hardness
TÜV · BV · Lloyds
Select the Right Grade for Your Service
C276 for mixed media. C22 for oxidising chloride/FGD. B3 for reducing HCl. All from one certified Mumbai facility.
Hastelloy C22 Stud Bolts
For FGD and oxidising chloride service — C22’s 22% Cr gives superior pitting resistance over C276 when oxidising chloride is the specific concern. Class 150–2500, M12–M100.
View Page →Hastelloy B3 Stud Bolts
For reducing HCl at all concentrations — B3’s high Mo without Cr gives near-zero corrosion in HCl where C276 shows only moderate resistance. Class 150–2500, M12–M100.
View Page →ASTM B574 Hastelloy Fasteners
Full C-series and B-series Hastelloy range under one ASTM standard. Grade selection matrix across all five grades — bolts, studs, nuts, washers, threaded rods.
View All Grades →Hastelloy Fasteners India
Complete Hastelloy manufacturer page — all six grades, all product forms, grade selection guidance. ISO 9001:2015 certified Mumbai facility. Export to 50+ countries.
View Range →Need Hastelloy C276
Fasteners Now?
Product form · size · quantity · matched set · documentation. Akbar Fasteners Pvt. Ltd. responds within 24 hours with full pricing, lead time, and MTC list.