Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
Hiduron Chemical Composition
Hiduron 130 (UNS C72400, Werkstoff 2.1504, CuNi14Al3Fe1) and Hiduron 191 (UNS C72420, CuNi14Mn4AlFe) are Cu-Ni-Al precipitation-hardened cupronickel alloys. Hiduron 130 carries roughly 81 percent copper balance with 14 to 15.5 percent nickel, 2.7 to 3.4 percent aluminium and 1.0 to 2.0 percent iron. Hiduron 191 keeps the nickel band but reduces aluminium to 1.5 to 2.5 percent and adds 4.0 to 5.0 percent manganese for solid-solution strengthening. The aluminium addition is the gamma-prime Ni3Al precursor that delivers the strength on age; the iron addition refines the grain and modifies the seawater oxide film; the manganese on 191 raises the work-hardening rate and lifts hot workability. The element role table below documents each addition.
Request Chemistry-Certified Hiduron 130 and 191 Stock and Fasteners
Hiduron 130 and Hiduron 191 Element Ranges (Percent by Weight)
| Element | Symbol | Hiduron 130, percent | Hiduron 191, percent | Metallurgical role |
|---|---|---|---|---|
| Copper | Cu | balance, ~80 to 82 | balance, ~76 to 78 | Matrix; seawater corrosion resistance and biofouling resistance |
| Nickel | Ni | 14.0 to 15.5 | 14.0 to 15.5 | Strengthening partner for gamma-prime Ni3Al precipitate |
| Aluminium | Al | 2.7 to 3.4 | 1.5 to 2.5 | Gamma-prime Ni3Al former; controls age-hardening response |
| Iron | Fe | 1.0 to 2.0 | 0.5 to 1.5 | Grain refinement; tunes seawater oxide film |
| Manganese | Mn | up to 0.75 | 4.0 to 5.0 | Solid-solution strengthening (191); hot-workability raiser |
| Silicon | Si | up to 0.10 | up to 0.10 | Deoxidiser residual from the melt |
| Lead | Pb | up to 0.02 | up to 0.02 | Tramp limit; protects hot ductility |
| Carbon | C | up to 0.05 | up to 0.05 | Tramp limit |
| Sulphur | S | up to 0.02 | up to 0.02 | Tramp limit |
| Zinc | Zn | up to 0.30 | up to 0.30 | Residual from copper feedstock |
Why Each Addition Matters in Service
Copper is the matrix and the source of the alloy's seawater resistance; the cupric oxide film that forms on a freshly polished Hiduron surface stabilises within hours of immersion and remains protective in low-flow, biofouling-prone, chloride-rich water where 316L suffers crevice attack. Nickel raises the strength of the FCC matrix and pairs with aluminium to form the gamma-prime Ni3Al precipitate on age. Aluminium is the strength-active element; the 3 percent loading on Hiduron 130 versus the 2 percent loading on Hiduron 191 is what gives the two grades their distinct strength bands. Iron is added to refine the grain and to modify the surface oxide so that the alloy stays protective in flowing seawater; the iron also raises the matrix work-hardening rate. Manganese on Hiduron 191 delivers solid-solution strengthening at room temperature and improves hot workability, which is why the 191 grade can be hot-forged into the larger naval and subsea bolting sizes more reliably than the 130.
Hiduron 130 + 191 Designation Chain
| Designation system | Hiduron 130 | Hiduron 191 |
|---|---|---|
| UNS (Unified Numbering System) | C72400 | C72420 |
| Werkstoff (German register) | 2.1504 | not formally assigned |
| Chemical-symbol designation | CuNi14Al3Fe1 | CuNi14Mn4AlFe |
| UK Air Ministry | DTD 900/4805 | not applicable |
| UK Naval Engineering Standard | not applicable | NES 835 |
| UK Ministry of Defence | not applicable | DEF STAN 02-835 |
| US Department of Defense | not applicable | DOD-C-24676 |
| Originator and brand | Langley Alloys (UK) | Langley Alloys (UK) |
Related Hiduron Property Pages
- Chemical Composition: Element ranges for both grades with role notes for each addition.
- Mechanical Properties: Yield, tensile, elongation and hardness at room and elevated temperature.
- Heat Treatment: Solution-anneal plus age cycle for gamma-prime Ni3Al precipitation.
- Seawater Corrosion: Cu-Ni-Al passive film behaviour in flowing seawater.
- SCC Resistance: Stress-corrosion cracking and hydrogen embrittlement immunity.
- Magnetic Permeability: Non-magnetic naval and aerospace qualification.
- Machinability: Cu-Ni-Al cutting parameters and tooling notes.
- Density and Physical Properties: Density, modulus, thermal expansion, conductivity.
Hiduron Forms TorqBolt Supplies
| Form factor | Standard sizes | Page |
|---|---|---|
| Round bar (raw stock) | OD 16 to 250 mm | Round Bar |
| Stud bolts | M12 to M100, 50 to 600 mm | Stud Bolts |
| Hex bolts (DIN 931 / ISO 4014) | M12 to M64 | Hex Bolts |
| Heavy hex bolts (ASME B18.2.1) | 1/2 to 3 inch | Heavy Hex Bolts |
| Nuts and heavy hex nuts | M12 to M100 | Nuts |
| Washers (flat, spring, locking) | M12 to M48 | Washers |
| Forgings (subsea connector blank) | up to 600 kg piece | Forgings |
| Machined components (custom) | to project drawing | Machined Components |
Where Hiduron Is Specified
- Subsea Connectors: Hiduron 130 flying-lead, stab-plate and umbilical termination bodies.
- Riser Bolting: Hiduron 191 splash-zone bolting on North Sea and Gulf of Mexico platforms.
- Splash Zone Bolting: Hiduron 191 fasteners for the wet-dry tidal band.
- Naval Fasteners: NES 835 and DEF STAN 02-835 procurement on Royal Navy and allied bolting.
- Pump Shafts and Valve Spindles: Marine pump shafts and subsea valve spindles.
- Mechanical Seals: Seal-face bodies against tungsten-carbide running faces.
- Propeller Shafts: Naval and commercial marine propeller shafts.
- Sour Service (NACE): NACE MR0175 qualified bolting for sour oil and gas service.
Hiduron Controlling Standards
| Standard | Scope | Relevance |
|---|---|---|
| NES 835 | UK Naval Engineering Standard for Cu-Ni-Al bolting | Hiduron 191 controlling spec |
| DEF STAN 02-835 | UK Ministry of Defence adoption of NES 835 | Hiduron 191 MoD procurement |
| DOD-C-24676 | US Department of Defense Cu-Ni-Al spec | Hiduron 191 US Navy procurement |
| DTD 900/4805 | UK Air Ministry specification | Hiduron 130 original spec |
| NACE MR0175 | Sour service materials qualification | Hiduron 191 qualified to 286 HBW limit |
EN 10204 Certification and Inspection
Every Hiduron 130 and Hiduron 191 stock and finished fastener ships with EN 10204 type 3.1 mill test certificate as standard. Type 3.2 third-party witness by Lloyd's Register, DNV, BV, SGS or TUV is supplied on call-out and is standard practice on naval and subsea procurement orders. The certificate carries the melt heat number, full chemical analysis to the controlling specification, solution-anneal plus age cycle parameters, tensile and yield results, hardness, Charpy V impact result where called out, and the dimensional report. For Hiduron 191 sour-service orders, an additional NACE MR0175 hardness certificate confirms that every test piece reads below the 286 HBW (28 HRC) limit.
Request a Quote on Hiduron Bolting
TorqBolt supplies Hiduron 130 (UNS C72400, DTD 900/4805) and Hiduron 191 (UNS C72420, NES 835, DEF STAN 02-835, DOD-C-24676) in round bar, stud bolts, hex bolts, heavy hex bolts, nuts, washers, forgings and machined components. Standard fastener lead time is 4 to 8 weeks from order, subsea machined components quote project-specific lead time. Send an enquiry through TorqBolt Contact with the controlling specification, the form factor, the size envelope and the certification level (3.1 default, 3.2 on call-out, NACE on call-out).
Request a Quote on Hiduron 130 and Hiduron 191 Bolting Stock and Fasteners
Reference and Downloads
- Hiduron 130 Datasheet: Consolidated chemistry, mechanicals and heat treatment.
- Hiduron 191 Datasheet: NACE-qualified naval and subsea grade datasheet.
- Bolt Dimensions: Imperial and metric thread, head and stress-area tables.
- Torque Chart: Cu-Ni-Al fastener torque values, dry and lubricated.
- FAQ: Consolidated questions on Hiduron specification, certification and supply.
Hiduron Chemistry FAQ
Q. Does Hiduron contain chromium?
No. Neither Hiduron 130 nor Hiduron 191 contains chromium. The corrosion resistance comes from the copper-nickel matrix and the cupric oxide passive film, not from a chromium-oxide film. That is why Hiduron stays protective in chloride-rich seawater where stainless steels suffer crevice and pitting attack.
Q. What is the difference in chemistry between Hiduron 130 and Hiduron 191?
Hiduron 130 carries 2.7 to 3.4 percent aluminium with up to 0.75 percent manganese; Hiduron 191 carries 1.5 to 2.5 percent aluminium with 4.0 to 5.0 percent manganese. The lower aluminium and the manganese addition on 191 raise the work-hardening rate and lift the hot-workability ceiling, which is why 191 is the grade used for the larger naval and splash-zone bolting sections.
Q. Is Hiduron the same chemistry as Nickel Aluminium Bronze?
No. Nickel Aluminium Bronze (UNS C95400) is a Cu-Al-Ni-Fe casting alloy with roughly 9 to 11 percent aluminium and 3 to 5 percent nickel. Hiduron is a Cu-Ni-Al cupronickel wrought alloy with 14 to 15.5 percent nickel and only 1.5 to 3.4 percent aluminium. The strengthening mechanism is different (gamma-prime Ni3Al on Hiduron versus kappa-phase on NAB) and the standards are different.
Q. Does Hiduron chemistry change between round bar, stud bolts and forgings?
No. The chemistry is set at the melt and stays uniform across all wrought forms. What changes between forms is the heat treatment cycle and the dimensional tolerance, not the chemistry. The same EN 10204 type 3.1 mill test certificate covers chemistry regardless of form factor.
Q. What is the tramp element limit on lead and sulphur?
Lead is held to 0.02 percent maximum and sulphur to 0.02 percent maximum on both grades. These are tramp limits set to protect hot ductility during forging and rolling; exceeding either threshold causes hot-shortness and is rejected at the melt.
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