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 and Hiduron 191 FAQ (Consolidated)
This page consolidates the most common questions on Hiduron 130 (UNS C72400, DTD 900/4805) and Hiduron 191 (UNS C72420, NES 835, DEF STAN 02-835, DOD-C-24676) across chemistry, mechanicals, heat treatment, seawater corrosion, stress-corrosion cracking, magnetic permeability, machinability, certification, lead time and standards cross-reference. Each answer cites the controlling standard and the design envelope. For project-specific clarification reach out through TorqBolt sales.
Basics: Alloy Family, Designations, Grades
Q. What is Hiduron?
Hiduron is a family of Cu-Ni-Al precipitation-hardened cupronickel alloys The two grades in commercial supply are Hiduron 130 (UNS C72400) and Hiduron 191 (UNS C72420). The strengthening mechanism is gamma-prime Ni3Al precipitation, analogous to Monel K-500 in nickel-base alloys.
Q. What is the difference between Hiduron 130 and Hiduron 191?
Hiduron 130 (UNS C72400, DTD 900/4805) is the mid-strength grade with 0.2 percent proof at least 480 MPa, used on subsea hydraulic connectors and aerospace bolting. Hiduron 191 (UNS C72420, NES 835, DEF STAN 02-835, DOD-C-24676) is the high-strength grade with 0.2 percent proof at least 580 MPa, qualified for NACE MR0175 sour service and used on splash-zone offshore bolting and naval bolting.
Q. Is Hiduron the same as Nickel Aluminium Bronze?
No. Nickel Aluminium Bronze (UNS C95400) is a Cu-Al-Ni-Fe casting alloy. Hiduron is a Cu-Ni-Al wrought cupronickel. The strengthening mechanism, the standards and the price level all differ.
Q. Who originated Hiduron?
Langley Alloys (UK) originated both Hiduron 130 and Hiduron 191. The alloys are registered under UNS C72400 and C72420 in the Copper Development Association database and are cross-listed in the UK Air Ministry, UK Naval Engineering, UK MoD and US DoD specification chains.
Chemistry and Composition
Q. Does Hiduron contain chromium?
No. Neither grade contains chromium. Corrosion resistance comes from the copper-nickel matrix and the cupric oxide passive film.
Q. What is the aluminium content?
Hiduron 130 carries 2.7 to 3.4 percent aluminium. Hiduron 191 carries 1.5 to 2.5 percent aluminium with 4.0 to 5.0 percent manganese added to balance the work-hardening and hot-workability response.
Q. What is the tramp limit on lead and sulphur?
0.02 percent maximum on both. Exceeding either threshold causes hot-shortness and is rejected at the melt.
Mechanical Properties
Q. What is the Hiduron 191 yield strength?
At least 580 MPa (0.2 percent proof) on solution-anneal plus age, with tensile 820 to 1000 MPa and elongation at least 15 percent.
Q. What is the Hiduron 130 yield strength?
At least 480 MPa (0.2 percent proof), tensile 740 to 850 MPa, elongation at least 18 percent.
Q. What is the service temperature ceiling?
350 deg C. Above this the gamma-prime Ni3Al precipitate over-coarsens and the strength on return cooling drops below the specification floor.
Q. What is the Charpy V impact at room temperature?
At least 60 J on Hiduron 130, at least 40 J on Hiduron 191. Both grades retain Charpy V impact above 25 J at minus 40 deg C.
Heat Treatment
Q. What is the solution-anneal temperature?
850 to 900 deg C, hold one hour to each 25 mm of section thickness, then water quench.
Q. What is the age temperature?
450 to 500 deg C for 2 to 4 hours followed by air cool. Hiduron 130 ages at the upper end, Hiduron 191 at the lower end of the band.
Q. Can Hiduron be re-solutioned and re-aged if the first cycle is off-spec?
Yes. The cycle is fully reversible without loss of toughness or fatigue endurance.
Seawater Corrosion, SCC and Hydrogen Embrittlement
Q. What is the seawater corrosion rate?
Less than 0.025 mm/year in flowing seawater at 1 to 3 m/s and 5 to 30 deg C on both grades.
Q. Does Hiduron suffer biofouling?
No. The copper-ion release at the surface suppresses macro-fouling settlement on submerged components.
Q. Is Hiduron 191 NACE MR0175 compliant?
Yes. Qualified to NACE MR0175 / ISO 15156 for sour-service bolting at or below 286 HBW (28 HRC).
Q. Is Hiduron immune to hydrogen embrittlement?
Yes. The Cu-Ni-Al FCC matrix has no hydrogen-trap sites of the kind that drive embrittlement on high-strength steel bolting under cathodic protection.
Q. Does Hiduron suffer chloride SCC?
No. The Cu-Ni-Al passive film is stable in flowing seawater and splash-zone exposure through the service envelope.
Physical Properties and Magnetic Response
Q. Is Hiduron non-magnetic?
Yes. mu_r below 1.005 on both grades. Qualified for naval mine-countermeasure and submarine bolting.
Q. What is the density?
8.85 g/cm3 on Hiduron 130 and 8.65 g/cm3 on Hiduron 191.
Q. What is the modulus of elasticity?
135 GPa on Hiduron 130 and 130 GPa on Hiduron 191. Roughly two-thirds of carbon-steel modulus.
Q. What is the thermal expansion coefficient?
16.5 x 10^-6 / K across the room-temperature to 300 deg C range on both grades.
Machinability and Welding
Q. What is the Hiduron machinability rating?
Roughly 30 percent of free-machining brass on Hiduron 130 aged, and 25 percent on Hiduron 191 aged.
Q. What cutting speed should I use?
Vc 60 to 100 m/min for turning with coated carbide TiAlN inserts. Flood coolant required to suppress built-up edge.
Q. Can Hiduron be welded?
Yes. Matched-composition filler under inert-gas shielding (gas tungsten arc with argon) with preheat 100 to 150 deg C and inter-pass below 250 deg C. Post-weld solution-anneal plus age restores parent properties through the joint.
Procurement, Certification, Lead Time
Q. What certification ships with Hiduron bolting?
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 on call-out. NACE MR0175 hardness certificate on call-out for Hiduron 191 sour-service orders.
Q. What is the standard lead time?
4 to 8 weeks on standard fastener sizes. Naval and sour-service certification orders quote project-specific lead time to accommodate the witness inspection schedule.
Q. What forms does TorqBolt supply?
Round bar, stud bolts, hex bolts, heavy hex bolts, anchor bolts, U-bolts, threaded rod, nuts, heavy hex nuts, washers, forgings and machined components. Sheet, plate, seamless pipe, tubing and wire are not commercial Hiduron forms.
Q. Where do I download the PDF datasheet?
PDF datasheets for both grades are available on request through TorqBolt sales. The on-page HTML datasheets at data-sheet-hiduron-130 and data-sheet-hiduron-191 consolidate the same content.
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
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.
Where Hiduron Sits Against Neighbouring Grades
| Grade | UNS | Service envelope | Comparison page |
|---|---|---|---|
| Monel K-500 | N05500 | Subsea bolting, sour service limited | Hiduron 130 vs Monel K-500 |
| 70/30 Cupronickel | C71500 | Seawater piping, no precipitation hardening | Hiduron vs C71500 |
| Cu-Ni-Cr | C72200 | Adjacent UNS, lower-strength cupronickel | Hiduron vs C72200 |
| Nickel Aluminium Bronze | C95400 | Cast propellers, marine valves | Hiduron vs C95400 |
| Hiduron 130 vs Hiduron 191 | C72400 vs C72420 | Strength against ductility trade-off | 130 vs 191 |
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.
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