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 vs Monel K-500
Hiduron 130 (UNS C72400), Hiduron 191 (UNS C72420) and Monel K-500 (UNS N05500) share the gamma-prime Ni3Al precipitation-hardening mechanism and compete directly in subsea bolting and naval fastener tenders. The matrix is the decisive difference: Hiduron is a copper-rich Cu-Ni-Al cupronickel (roughly 80 percent copper); Monel K-500 is a nickel-rich Ni-Cu alloy (roughly 65 percent nickel). That matrix shift has three procurement-binding consequences: Hiduron 191 qualifies under NACE MR0175 at the 286 HBW (28 HRC) hardness ceiling while age-hardened Monel K-500 bar routinely exceeds its own 35 HRC cap and is excluded; both Hiduron grades hold magnetic permeability below 1.005 mu_r by alloy class while Monel K-500 permeability drifts above the limit on certain heat lots; and Hiduron carries copper-matrix biofouling resistance that the nickel-dominant Monel matrix does not replicate. Specify Hiduron 191 when NACE compliance and non-magnetic response are simultaneously binding constraints.
At a Glance: Hiduron vs Monel K-500
| Property | Hiduron 130 (C72400) | Hiduron 191 (C72420) | Monel K-500 (N05500) |
|---|---|---|---|
| Matrix | Cu-Ni-Al cupronickel | Cu-Ni-Mn-Al cupronickel | Ni-Cu alloy |
| Strengthening | Gamma-prime Ni3Al | Gamma-prime Ni3Al + Mn solid solution | Gamma-prime Ni3(Al,Ti) |
| Tensile (Rm) | 740 to 850 MPa | 820 to 1000 MPa | 900 to 1100 MPa |
| 0.2 percent proof | >=480 MPa | >=580 MPa | >=620 MPa |
| NACE MR0175 hardness | n/a primary | <=286 HBW / 28 HRC, qualified | 35 HRC strict cap, often breached |
| Magnetic permeability | <1.005 mu_r | <1.005 mu_r | typically 1.0005 to 1.020 mu_r |
| Seawater corrosion | Excellent (Cu-Ni matrix) | Excellent (Cu-Ni-Mn matrix) | Excellent (Ni-Cu matrix) |
| Procurement spec | DTD 900/4805 | NES 835, DEF STAN 02-835, DOD-C-24676 | ASTM B865, QQ-N-286 |
Chemistry Comparison
| Element | Hiduron 130 typical | Hiduron 191 typical | Monel K-500 typical |
|---|---|---|---|
| Cu | balance (~80 to 82) | balance (~76 to 78) | 27 to 33 |
| Ni | 14.0 to 15.5 | 14.0 to 15.5 | balance (~63 to 70) |
| Al | 2.7 to 3.4 | 1.5 to 2.5 | 2.3 to 3.15 |
| Ti | n/a | n/a | 0.35 to 0.85 |
| Mn | up to 0.75 | 4.0 to 5.0 | up to 1.5 |
| Fe | 1.0 to 2.0 | 0.5 to 1.5 | up to 2.0 |
When to Specify Hiduron vs Monel K-500
- Specify Hiduron 191 when the application carries a NACE MR0175 sour-service requirement and the hardness ceiling at 286 HBW (28 HRC) is binding. Hiduron 191 is qualified at the ceiling; Monel K-500 commonly drifts above its own 35 HRC cap on age-hardened bar and is excluded.
- Specify Hiduron 191 when the application carries a naval mine-countermeasures requirement and the magnetic permeability must hold below 1.005 mu_r. Hiduron 191 holds the limit by alloy class; Monel K-500 magnetic permeability drifts above the limit on certain heat lots.
- Specify Hiduron 130 when the application is a subsea hydraulic or electrical connector body where the DTD 900/4805 traceability chain is required and the mid-strength envelope (Rp0.2 above 480 MPa) is sufficient.
- Specify Monel K-500 when the application is non-NACE, non-naval, and the higher strength envelope (Rp0.2 above 620 MPa) drives the selection. K-500 sits adjacent to Hiduron 191 in this case and either alloy can be supplied to the same project.
Form Availability
Hiduron 130 and Hiduron 191 are supplied in the bolting form range (round bar, stud bolts, hex bolts, heavy hex bolts, anchor bolts, U-bolts, threaded rod, nuts, heavy hex nuts, washers, forgings, machined components) detailed in the shared Forms block below. Monel K-500 is supplied in the same bolting form range from adjacent mill sources. Cross-reference procurement that needs a single supplier across both alloys is standard for shortlist projects where the materials selection is open until late.
Frequently Asked Questions
Q. Is Hiduron 191 a Monel K-500 replacement?
For subsea hydraulic connectors and naval bolting where Monel K-500 hardness exceeds the NACE MR0175 limit, Hiduron 191 is the direct replacement. The two grades share the gamma-prime strengthening mechanism and overlap in the subsea bolting service envelope, but Hiduron 191 is NACE-qualified at the 286 HBW (28 HRC) ceiling and Monel K-500 is hardness-restricted at 35 HRC, commonly above ceiling on age-hardened bar.
Q. What is the chemistry difference between Hiduron and Monel K-500?
Hiduron is a copper-rich Cu-Ni-Al cupronickel (Cu balance, Ni 14 to 15.5 percent, Al 1.5 to 3.4 percent). Monel K-500 is a nickel-rich Ni-Cu alloy (Ni 63 to 70 percent balance, Cu 27 to 33 percent, Al 2.3 to 3.15 percent, Ti 0.35 to 0.85 percent). The strengthening mechanism is identical (gamma-prime precipitation) but the matrix is different.
Q. Which is non-magnetic?
Both Hiduron 130 and Hiduron 191 hold magnetic permeability below 1.005 mu_r by alloy class and are qualified for Royal Navy mine-countermeasures applications. Monel K-500 magnetic permeability drifts above the 1.005 ceiling on certain heat lots and can be disqualified on the same applications.
Q. Do they share the same procurement standards?
No. Hiduron 191 procurement traceability is NES 835, DEF STAN 02-835 and DOD-C-24676. Monel K-500 procurement is ASTM B865 (bolting bar) and QQ-N-286 (US federal). Cross-reference projects cite both chains on the materials selection table and pick the alloy that lands inside the binding constraint (NACE hardness, magnetic permeability, or strength envelope).
Q. Do you supply Hiduron 191 with dual NACE + naval certification?
Yes. EN 10204 type 3.1 mill test certificate with both the NACE MR0175 hardness statement and the NES 835 / DEF STAN 02-835 / DOD-C-24676 chemistry plus mechanical traceability on the same heat. Type 3.2 with Lloyd's, DNV, BV, SGS or TUV witness on call-out.
Satisfaction Survey
