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 130 + 191 Cu-Ni-Al Precipitation-Hardened Cupronickel
Hiduron 130 (UNS C72400, Werkstoff 2.1504, CuNi14Al3Fe1, DTD 900/4805) and Hiduron 191 (UNS C72420, NES 835, DEF STAN 02-835, DOD-C-24676) are nickel-aluminium-iron precipitation-hardened cupronickel alloys The strengthening mechanism is gamma-prime Ni3Al precipitation analogous to Monel K-500. Both grades are non-magnetic, anti-galling, anti-biofouling and immune to hydrogen embrittlement, which is why North Sea and Gulf of Mexico operators specify them for splash-zone bolting and subsea connector bodies where Monel K-500 hardness limits are too restrictive.
Request a Quote on Hiduron 130 and Hiduron 191 Bolting Stock and Fasteners
Hiduron International Designations and Equivalents
The Hiduron family has a stable cross-reference chain across UK Air Ministry, UK Ministry of Defence, US Department of Defense and UNS designations. Hiduron 130 is registered as UNS C72400 in the Copper Development Association database and as Werkstoff 2.1504 in the German steel-numbers register, with the chemical-symbol designation CuNi14Al3Fe1. The original UK Air Ministry specification is DTD 900/4805. Hiduron 191 carries UNS C72420 with the UK Naval Engineering Standard NES 835 as the procurement spec for naval surface and submarine bolting. NES 835 was adopted by the UK Ministry of Defence as DEF STAN 02-835 and is cross-referenced by the US Department of Defense as DOD-C-24676 for naval procurement. The Hiduron trade name itself is the Langley Alloys brand for both grades.
| 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 |
| Legacy aerospace | Hidurax Special | EB4223A |
| Originator / brand | Langley Alloys (UK) | Langley Alloys (UK) |
Hiduron Chemical Composition (Cu-Ni-Al Family)
| Element | Hiduron 130 typical, percent | Hiduron 191 typical, percent | Role |
|---|---|---|---|
| Copper (Cu) | balance (~80 to 82) | balance (~76 to 78) | Matrix; seawater corrosion resistance |
| Nickel (Ni) | 14.0 to 15.5 | 14.0 to 15.5 | Strengthening partner for gamma-prime Ni3Al |
| Aluminium (Al) | 2.7 to 3.4 | 1.5 to 2.5 | Gamma-prime former; precipitation hardening |
| Iron (Fe) | 1.0 to 2.0 | 0.5 to 1.5 | Grain refinement; corrosion modifier |
| Manganese (Mn) | up to 0.75 | 4.0 to 5.0 | Solid-solution strengthening (191) |
| Silicon (Si) | up to 0.10 | up to 0.10 | Deoxidation residual |
| Lead (Pb) | up to 0.02 | up to 0.02 | Tramp limit for hot workability |
| Carbon (C) | up to 0.05 | up to 0.05 | Tramp limit |
Hiduron Mechanical Properties (Solution Annealed + Aged)
| Property | Hiduron 130 | Hiduron 191 | Test condition |
|---|---|---|---|
| Tensile strength (Rm) | 740 to 850 MPa | 820 to 1000 MPa | RT, SA+aged |
| 0.2 percent proof stress (Rp0.2) | >=480 MPa | >=580 MPa | RT, SA+aged |
| Elongation A5 | >=18 percent | >=15 percent | RT, longitudinal |
| Hardness (HV) | 240 to 280 | 270 to 320 | RT, Vickers |
| Hardness (HBW), max for sour service | n/a (not NACE) | <=28 HRC / <=286 HBW | NACE MR0175 limit |
| Charpy V impact at room temperature | >=60 J | >=40 J | RT, longitudinal |
| Magnetic permeability | <1.005 mu_r | <1.005 mu_r | Non-magnetic, naval qualified |
| Density | 8.85 g/cm3 | 8.65 g/cm3 | Calculated from chemistry |
Where Hiduron Is Specified (Subsea, Naval, Splash-Zone)
The Hiduron family is specified into subsea hydraulic and electrical connectors, riser bolting on offshore platforms, splash-zone fasteners, naval surface and submarine bolting, propeller shafts, valve spindles, pump shafts and mechanical seal faces. The 8 primary service areas are linked from the Applications dropdown above and from the body block below. The decisive selection drivers are NACE MR0175 sour-service compliance, hydrogen-embrittlement immunity, non-magnetic response and seawater biofouling resistance, in combination with high yield strength above the level that conventional 70/30 cupronickel can deliver.
- Subsea Connectors: Hiduron 130 flying-lead, stab-plate and umbilical termination bodies for subsea hydraulic and electrical control systems.
- Riser Bolting: Hiduron 191 splash-zone bolting on North Sea and Gulf of Mexico offshore platform risers, with over 15 years of in-service performance.
- Splash Zone Bolting: Hiduron 191 fasteners for the wet-dry tidal band where stainless steels suffer chloride crevice attack.
- Naval Fasteners: NES 835 and DEF STAN 02-835 procurement on UK Royal Navy and allied surface and submarine bolting.
- Pump Shafts and Valve Spindles: Marine pump shafts and subsea valve spindles where anti-galling and corrosion fatigue performance are decisive.
- Mechanical Seals: Seal-face bodies that need anti-galling against tungsten-carbide and silicon-carbide running faces.
- Propeller Shafts: Naval and commercial marine propeller shafts and drive bushes.
- Sour Service (NACE): NACE MR0175 / ISO 15156 qualified bolting for sour oil and gas service.
Where Hiduron Sits Against Neighbouring Cu-Ni-Al Grades
| Grade | UNS | Service envelope | Why choose / when to step |
|---|---|---|---|
| Monel K-500 | N05500 | Subsea, sour service (gauges) | Step UP to Hiduron 191 when NACE MR0175 hardness limits exclude K-500 |
| Hiduron 191 | C72420 | Naval, subsea, splash zone, sour service | Highest-strength NACE-compliant Cu-Ni-Al; non-magnetic |
| Hiduron 130 | C72400 | Subsea hydraulic connectors, marine | Mid-strength Cu-Ni-Al; subsea connector flagship grade |
| Nickel Aluminium Bronze (NAB) | C95400 | Propellers, marine valves | Different alloy family (Cu-Al-Ni-Fe); not interchangeable with Hiduron |
| 70/30 Cupronickel | C71500 | Seawater piping | Lower strength; Hiduron replaces it where structural load matters |
| Nibron Special | n/a (proprietary) | Naval bolting (Columbia Metals) | Equivalent positioning to Hiduron 191; NES 835 cross-qualified |
| Toughmet 3 (C72900) | C72900 | Subsea connectors (Materion) | Spinodally-strengthened Cu-Ni-Sn; adjacent positioning to Hiduron 191 |
Hiduron Forms and Fasteners
TorqBolt supplies Hiduron 130 and Hiduron 191 in the bolting and machined-component form range that the Langley Alloys catalogue confirms is commercially available. Round bar is the primary stock, hot worked to NES 835 and DTD 900/4805 dimensional and chemistry control. Forging stock and finished forgings are supplied for subsea connector blanks and large-section components. Finished fasteners are machined from solution-annealed bar and age-treated in the finished condition. Machined components (subsea connector bodies, valve spindles, pump shafts) are produced from forged blanks against project drawings. All product is supplied with EN 10204 type 3.1 mill test certificate by default, type 3.2 with Lloyd's Register, DNV, BV, SGS or TUV witness on call-out, and NACE MR0175 hardness certificate on call-out for Hiduron 191 sour-service orders.
| Form factor | Standard sizes | Page |
|---|---|---|
| Round bar (raw) | OD 16 to 250 mm | Round Bar |
| Stud bolts (flange bolting) | M12 to M100, lengths 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" | Heavy Hex Bolts |
| Anchor bolts | M16 to M64 | Anchor Bolts |
| U-bolts (pipe support) | per project drawing | U-Bolts |
| Threaded rod | M12 to M48, cut to length | Threaded Rod |
| Nuts (matched-grade hex) | M12 to M100 | Nuts |
| Heavy hex nuts (matched-grade) | M16 to M100 | Heavy Hex Nuts |
| Washers (flat, spring, locking) | M12 to M48 | Washers |
| Forgings (subsea connector blank) | up to 600 kg piece | Forgings |
| Machined components (custom) | per project drawing | Machined Components |
TorqBolt Hiduron Track Record
TorqBolt supplies Hiduron 130 and Hiduron 191 into the global subsea, naval and offshore bolting market with end-to-end quality control from heat traceability through final NACE-hardness witness.
- 2023 — North Sea operator, 240 pcs Hiduron 191 M64 heavy hex stud bolts for splash-zone riser tie-in, EN 10204 type 3.2 with DNV witness, NACE MR0175 hardness reading per stud.
- 2022 — Subsea EPC, 84 pcs Hiduron 130 forged connector body blanks to Langley Alloys CS32 dimensions, finished-machined and aged in-house, LR type 3.2.
- 2021 — UK MoD-tier shipyard, Hiduron 191 naval fastener pack per NES 835 / DEF STAN 02-835, full traceability + magnetic permeability witness below 1.005 mu_r.
- 2020 — present — Gulf of Mexico operator, repeat supply of Hiduron 191 stud bolts and machined components for sour-service bolting, NACE qualification on file.
Hiduron Frequently Asked Questions
Q. What is the difference between Hiduron 130 and Hiduron 191?
Hiduron 130 (UNS C72400) is the mid-strength Cu-Ni-Al grade specified into subsea hydraulic connectors and general marine service to DTD 900/4805. Hiduron 191 (UNS C72420) is the higher-strength manganese-modified grade specified into naval bolting and splash-zone offshore bolting to NES 835, DEF STAN 02-835 and DOD-C-24676. Hiduron 191 is the grade qualified for NACE MR0175 sour service.
Q. Is Hiduron 191 NACE MR0175 compliant?
Yes. Hiduron 191 is qualified to NACE MR0175 / ISO 15156 for sour-service bolting on the standard solution-anneal plus age cycle, provided hardness is controlled below 286 HBW (28 HRC). The mill test certificate carries the hardness reading per stud as NACE compliance evidence.
Q. Is Hiduron the same as Nickel Aluminium Bronze?
No. Hiduron is a Cu-Ni-Al precipitation-hardened cupronickel (gamma-prime Ni3Al strengthening). Nickel Aluminium Bronze is UNS C95400, a Cu-Al-Ni-Fe casting alloy with a different strengthening mechanism. They are different alloy classes with different specifications and welding behaviour.
Q. Do you supply Hiduron with EN 10204 type 3.2 certification?
Yes. Type 3.1 is supplied by default with heat number, chemistry, solution-anneal plus age cycle, mechanical results, hardness and dimensional report. Type 3.2 with Lloyd's Register, DNV, BV, SGS or TUV witness is supplied on call-out and is standard practice on naval and subsea procurement.
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