Precision-engineered Hastelloy C276, C22, B2, B3 & Grade X hex bolts, stud bolts, heavy hex nuts, and socket cap screws built strictly to ASTM B574 and ASME B18.2.1 standards.
Extreme Resistance to Wet Chlorine & Strong Acids
Formulated with tungsten and high molybdenum to eliminate pitting, crevice corrosion, and stress corrosion cracking in aggressive process fluids.
Global Fastener Partner for 105+ Countries
Complete Positive Material Identification (PMI), NACE MR0175/ISO 15156 compliance, and seaworthy export packaging for turnkey EPC contractors.
Hex bolts, heavy hex bolts, socket head cap screws, and square head bolts in Hastelloy C276, C22, and B3 engineered for structural integrity in acid reactors.
Continuous threaded studs, double-end tap studs, and flange studs designed for high-pressure gasket sealing in sour gas and desulfurization systems.
Heavy hex nuts, lock nuts, flat washers, and Belleville spring washers manufactured from Hastelloy matrix to prevent galvanic coupling failures.
Understanding the chemistry, phase stability, and localized corrosion mechanisms of Hastelloy C276, C22, B2, B3, and Grade X fasteners.
When industrial piping systems, chemical reactors, heat exchangers, and flue-gas desulfurization (FGD) scrubbers operate under aggressive chemical exposure, standard 316L stainless steel, duplex 2205, or even 300-series alloys experience catastrophic failure due to pitting, crevice corrosion, or chloride stress corrosion cracking (SCC). In these mission-critical environments, Hastelloy fasteners—manufactured from nickel-chromium-molybdenum and nickel-molybdenum superalloys—provide the ultimate level of structural and chemical reliability.
At Neelkamal Alloys LLP, our metallurgical engineers select and machine prime-grade bar stock conforming strictly to ASTM B574 (UNS N10276, UNS N06022, UNS N10665, UNS N10675) to ensure that every hex bolt, stud bolt, heavy hex nut, and socket cap screw maintains structural integrity under extreme hydrostatic and thermal stress.
The corrosion resistance of Hastelloy fasteners is directly dictated by their elemental composition. Molybdenum provides resistance to reducing acids and localized pitting, Chromium delivers protection against oxidizing media, and Tungsten enhances resistance to pit formation in halide-rich environments.
| Hastelloy Alloy | UNS Designation | Nickel (Ni) % | Chromium (Cr) % | Molybdenum (Mo) % | Iron (Fe) % | Tungsten (W) % | Primary Application Environment |
|---|---|---|---|---|---|---|---|
| Hastelloy C276 | UNS N10276 | Balance (~57) | 14.5 – 16.5 | 15.0 – 17.0 | 4.0 – 7.0 | 3.0 – 4.5 | Ferric/cupric chlorides, wet chlorine gas, acetic anhydride, hot sea water |
| Hastelloy C22 | UNS N06022 | Balance (~56) | 20.0 – 22.5 | 12.5 – 14.5 | 2.0 – 6.0 | 2.5 – 3.5 | Severe oxidizing acids, nitric acid mixtures, aggressive chloride pitting service |
| Hastelloy B2 | UNS N10665 | Balance (~68) | 1.0 max | 26.0 – 30.0 | 2.0 max | — | Pure hydrochloric acid (HCl), sulfuric acid without oxidizing impurities |
| Hastelloy B3 | UNS N10675 | Balance (~65) | 1.0 – 3.0 | 27.0 – 32.0 | 1.0 – 3.0 | 3.0 max | HCl, acetic acid, formic acid with superior thermal stability over B2 |
| Hastelloy X | UNS N06002 | Balance (~47) | 20.5 – 23.0 | 8.0 – 10.0 | 17.0 – 20.0 | 0.2 – 1.0 | High-temperature industrial furnaces, gas turbine bolting up to 1200°C |
The Pitting Resistance Equivalent Number (PREN) evaluates a metal's immunity to localized chloride attack. While super duplex 2507 achieves a PREN of ~42, Hastelloy C276 reaches a PREN exceeding 68, calculated via the extended formula:
PREN = %Cr + 3.3(%Mo + 0.5*%W) + 16*%N This exceptionally high rating explains why Hastelloy C276 stud bolts remain immune to pitting and crevice corrosion in boiling 10% ferric chloride ($FeCl_3$) solutions, hyper-saline desalination brine, and sour oilfield environments containing dissolved hydrogen sulfide ($H_2S$) and carbon dioxide ($CO_2$).
Neelkamal Alloys LLP stands as a premier global manufacturer, stockist, and exporter of high-integrity Hastelloy bolts, stud bolts, hex nuts, washers, and specialized CNC custom fasteners. Operating from our advanced manufacturing hub in Mumbai, India, we serve EPC project managers, procurement directors, and maintenance engineers in over 105 countries.
High-nickel alloys require specialized machining parameters, precision tool geometry, and strict thermal control during thread rolling and cold heading. Our facility utilizes multi-axis CNC turning centers, automatic thread rolling machines, and solution annealing furnaces to ensure that every Hastelloy C276, C22, and B3 fastener maintains exact pitch tolerances and maximum fatigue strength.
Mechanical design values and engineering torque charts for Hastelloy C276 fasteners under lubricated and dry installation conditions.
| Grade / Condition | Tensile Strength (MPa / ksi) min | Yield Strength 0.2% Offset (MPa / ksi) min | Elongation in 2 in. (%) min | Hardness (Rockwell B / C) max | Density ($g/cm^3$) |
|---|---|---|---|---|---|
| Hastelloy C276 (Solution Annealed) | 690 MPa / 100 ksi | 283 MPa / 41 ksi | 40% | HRB 100 / HRC 20 max | 8.89 $g/cm^3$ |
| Hastelloy C22 (Solution Annealed) | 690 MPa / 100 ksi | 310 MPa / 45 ksi | 45% | HRB 93 max | 8.69 $g/cm^3$ |
| Hastelloy B2 (Solution Annealed) | 760 MPa / 110 ksi | 350 MPa / 51 ksi | 40% | HRB 100 max | 9.22 $g/cm^3$ |
| Hastelloy B3 (Solution Annealed) | 785 MPa / 114 ksi | 350 MPa / 51 ksi | 40% | HRB 100 max | 9.22 $g/cm^3$ |
| Hastelloy X (Solution Annealed) | 655 MPa / 95 ksi | 240 MPa / 35 ksi | 35% | HRB 95 max | 8.22 $g/cm^3$ |
Values based on 65% of minimum yield strength utilizing anti-seize lubricant ($K = 0.12$) vs dry assembly ($K = 0.20$).
| Nominal Thread Size | Threads Per Inch (TPI / Pitch) | Stress Area ($in^2 / mm^2$) | Clamp Load (lbs / kN) | Recommended Torque (Lubricated, ft-lbs) | Recommended Torque (Dry Assembly, ft-lbs) |
|---|---|---|---|---|---|
| 1/2" - 13 UNC | 13 TPI | 0.1419 $in^2$ | 3,780 lbs | 32 ft-lbs | 52 ft-lbs |
| 5/8" - 11 UNC | 11 TPI | 0.2260 $in^2$ | 6,020 lbs | 64 ft-lbs | 104 ft-lbs |
| 3/4" - 10 UNC | 10 TPI | 0.3340 $in^2$ | 8,900 lbs | 112 ft-lbs | 185 ft-lbs |
| 7/8" - 9 UNC | 9 TPI | 0.4620 $in^2$ | 12,300 lbs | 180 ft-lbs | 295 ft-lbs |
| 1" - 8 UNC | 8 TPI | 0.6060 $in^2$ | 16,100 lbs | 270 ft-lbs | 445 ft-lbs |
| 1-1/8" - 8 UN | 8 TPI | 0.7900 $in^2$ | 21,000 lbs | 395 ft-lbs | 650 ft-lbs |
| 1-1/4" - 8 UN | 8 TPI | 1.0000 $in^2$ | 26,600 lbs | 555 ft-lbs | 915 ft-lbs |
| M12 x 1.75 | 1.75 mm pitch | 84.3 $mm^2$ | 15.5 kN | 38 N·m | 62 N·m |
| M16 x 2.0 | 2.00 mm pitch | 157.0 $mm^2$ | 28.8 kN | 92 N·m | 150 N·m |
| M20 x 2.5 | 2.50 mm pitch | 245.0 $mm^2$ | 45.0 kN | 180 N·m | 295 N·m |
Threads are cold-rolled rather than cut to introduce compressive residual stress, increasing fatigue life by up to 300%.
Heat treatment at 1150°C followed by rapid water quenching restores grain microstructure and optimizes corrosion resistance.
Application of PTFE, Xylan, or MoS2 micro-coatings eliminates adhesive friction and cold welding during high-torque assembly.
Ultrasonic inspection, dye-penetrant testing, and PMI verification guarantee defect-free fasteners for pressure vessel duty.
Exotic alloy bolting products manufactured to ASME, DIN, ISO, and client-specific engineering drawings.
UNS N10276 / 2.4819 hex head and heavy hex bolts for severe acid service, chlorination systems, and paper pulp digesters.
View ProductUNS N06022 all-thread stud bolts and double-end studs providing ultimate protection in oxidizing and chloride media.
View ProductUNS N10665 & N10675 screws and nuts engineered for pure hydrochloric acid handling and chemical synthesis reactors.
View ProductUNS N06002 high-temperature fasteners designed for thermal oxidation resistance up to 1200°C in jet engines and furnaces.
View ProductAnalyzing key global shifts impacting supply chain strategy, raw material nickel dynamics, and next-generation engineering requirements.
As the global energy sector transitions to zero-emission green hydrogen production, proton exchange membrane (PEM) and alkaline electrolyzers operate at elevated temperatures with corrosive KOH and wet halogen gas streams. Procurement demand for Hastelloy C276 and C22 stud bolts is projected to increase by 28% annually through 2030, replacing standard 316L fasteners in cell-stack tie rods and high-pressure manifold joints.
Global EPC procurement teams are rapidly mitigating geopolitical supply concentration by establishing direct relationships with certified Indian manufacturers like Neelkamal Alloys LLP. Indian specialty fastener mills offer ISO-certified manufacturing, full EN 10204 3.1 material traceability, and competitive lead times without sacrificing stringent Western QA/QC metrics.
High-nickel alloys naturally exhibit adhesive wear during high-load torque assembly. Technological advances in physical vapor deposition (PVD), ceramic micro-layers, and fluoropolymer PTFE co-coatings allow Hastelloy fasteners to achieve low, consistent friction coefficients ($K = 0.10 - 0.12$) without contaminating sensitive high-purity pharmaceutical or chemical lines.
Volatility in London Metal Exchange (LME) nickel pricing requires procurement managers to adopt long-term supply agreements with standardized alloy surcharges. Neelkamal Alloys LLP supports global buyers with price-lock contracts, buffer stock management, and just-in-time delivery for major shutdown turnarounds.
Key indicators reflecting our engineering capacity, material inventory, and international market trust.
Engineered to operate reliably where chemical exposure, extreme heat, and severe pressure exceed standard alloy limits.
Reactors, heat exchangers, distillation columns, and acid piping systems.
NACE MR0175 compliant bolting for downhole tools and subsea manifolds.
FGD scrubber units handling wet sulfur dioxide ($SO_2$) and acidic slurries.
Fasteners for acetic acid, formic acid, and vinyl acetate monomer (VAM) units.
High-pressure reverse osmosis pumps and nuclear waste processing containment.
Phosphoric acid concentration plants and bleach plant washers in pulp production.
Detailed engineering and procurement answers regarding material grades, international standards, testing procedures, and torque mechanics.
Contact UsHastelloy C276 (UNS N10276) contains approximately 16% Chromium, 16% Molybdenum, and 3.7% Tungsten, making it exceptional in reducing acids, wet chlorine gas, ferric chloride, and hypochlorites. Hastelloy C22 (UNS N06022) increases Chromium content to 22% while maintaining 13% Molybdenum and 3% Tungsten. Consequently, C22 exhibits significantly superior resistance in aggressive, highly oxidizing aqueous environments, mixed nitric/hydrofluoric acids, and chloride-induced pitting, whereas C276 performs better in strongly reducing conditions.
Hastelloy B2 (UNS N10665) and Hastelloy B3 (UNS N10675) are Nickel-Molybdenum alloys designed specifically to resist hydrochloric acid (HCl) at all concentrations and temperatures up to boiling. Austenitic stainless steels (like 316L) suffer immediate stress corrosion cracking and rapid uniform corrosion in pure HCl. Hastelloy B3 offers enhanced thermal stability over B2, preventing intergranular corrosion and grain-boundary precipitation during hot fabrication and welding processes.
Thread galling is adhesive wear caused by high friction and pressure between mating high-nickel metal surfaces during tightening. To prevent galling in Hastelloy C276 and C22 bolting assemblies, engineering teams should apply molybdenum disulfide (MoS2) or silver-based anti-seize lubricants, utilize precision-rolled threads rather than cut threads, maintain recommended assembly torque speeds, or combine Hastelloy bolts with hard-coated or dissimilar nickel-alloy heavy hex nuts.
Neelkamal Alloys LLP manufactures Hastelloy fasteners in strict accordance with material standards including ASTM B574 (Rod/Bar), ASTM B575 (Plate/Sheet), ASTM B619/B622 (Tubular products for sleeve anchors), and dimensional specs including ASME B18.2.1 (Hex/Heavy Hex Bolts), ASME B18.2.2 (Nuts), DIN 931/933, DIN 975/976 (Stud Bolts), ISO 4014/4017, and NACE MR0175/ISO 15156 for sour oil & gas service.
Yes. All Hastelloy export orders from Neelkamal Alloys LLP are dispatched with full EN 10204 3.1 Mill Test Certificates (MTC) detailing melt heat numbers, mechanical tensile/yield testing, chemical composition via optical emission spectrometry, microstructural examination, and PMI (Positive Material Identification). Third-party inspection (TPI) by agencies such as Lloyd's Register, TUV, Bureau Veritas, or SGS is routinely arranged based on client Quality Assurance Plans (QAP).
Hastelloy C276 fasteners are typically limited to continuous operating temperatures of 1000°F (538°C) in oxidizing environments because exposure above this range can form embrittling intermetallic phases. For higher temperature duty, Hastelloy X (UNS N06002) is recommended, as it maintains mechanical strength and oxidation resistance at temperatures up to 2200°F (1200°C), making it ideal for gas turbine and furnace structural bolting.
Neelkamal Alloys LLP maintains extensive raw bar inventory in Hastelloy C276 and C22 from 1/4" (6mm) to 4" (100mm) diameters. Standard hex bolts and stud bolts are available for immediate stock dispatch. Custom CNC machined components or special thread pitch bolts manufactured to client engineering drawings typically ship within 10 to 15 working days, with express air freight options available for emergency plant turnarounds.
Combining metallurgical expertise, robust manufacturing infrastructure, and uncompromised quality assurance.
Every Hastelloy bar is sourced exclusively from tier-1 primary melt producers with full heat-number traceability retained throughout forging, machining, and dispatch.
Our quality control center is equipped with Spectro analysis, Positive Material Identification (PMI), Rockwell/Vickers hardness testers, optical shadow graph Thread Pitch Gauge, and tensile test rigs.
Fasteners are treated with anti-corrosion protective oil, individually capped, packed into vacuum-sealed vapor corrosion inhibitor (VCI) bags, and secured in heat-treated ISPM-15 wooden crates.
Submit your material grade, fastener dimensions, standard specifications, and target delivery timeframe. Our senior metallurgy team will review your inquiry and deliver a competitive technical bid within 24 hours.
