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 Nibron Special
Hiduron 191 (UNS C72420) and Nibron Special are two trade-name designations for the same Cu-Ni-Al-Mn precipitation-hardened cupronickel alloy family qualified under the UK Naval Engineering Standard NES 835 and the UK Ministry of Defence DEF STAN 02-835. Both alloys land at the same procurement envelope: nickel 14 to 15.5 percent, manganese 4 to 5 percent, aluminium 1.5 to 2.5 percent, balance copper, with the gamma-prime Ni3Al precipitation-hardening response and the 286 HBW (28 HRC) hardness ceiling for NACE MR0175 sour-service compliance. The two trade names exist because the alloy class is supplied by parallel UK mill sources under different brand identities; the underlying procurement specifications are identical.
At a Glance: Hiduron 191 vs Nibron Special
| Property | Hiduron 191 | Nibron Special |
|---|---|---|
| UNS | C72420 | C72420 (same UNS) |
| Family | Cu-Ni-Mn-Al precip-hardened | Cu-Ni-Mn-Al precip-hardened |
| Strengthening | Gamma-prime Ni3Al + Mn solid solution | Gamma-prime Ni3Al + Mn solid solution |
| Tensile (Rm) | 820 to 1000 MPa | 820 to 1000 MPa |
| 0.2 percent proof | >=580 MPa | >=580 MPa |
| Hardness ceiling | <=286 HBW / 28 HRC for NACE | <=286 HBW / 28 HRC for NACE |
| NES 835 | Primary procurement spec | Primary procurement spec |
| DEF STAN 02-835 | UK MoD procurement | UK MoD procurement |
| DOD-C-24676 | US DoD procurement | US DoD procurement |
| Magnetic permeability | <1.005 mu_r | <1.005 mu_r |
Chemistry Comparison
| Element | Hiduron 191 typical | Nibron Special typical |
|---|---|---|
| Cu | balance (~76 to 78) | balance (~76 to 78) |
| Ni | 14.0 to 15.5 | 14.0 to 15.5 |
| Mn | 4.0 to 5.0 | 4.0 to 5.0 |
| Al | 1.5 to 2.5 | 1.5 to 2.5 |
| Fe | 0.5 to 1.5 | 0.5 to 1.5 |
When to Specify Hiduron 191 vs Nibron Special
- Specify either trade name to the procurement standard (NES 835, DEF STAN 02-835 or DOD-C-24676) and the supplier is free to ship the heat that meets the specification. The underlying alloy class is identical; the trade-name distinction is brand identity, not technical content.
- Use Hiduron 191 on UK Air Ministry, Royal Navy and US Navy procurement where the buyer or specifier has a habit of using the Hiduron designation. The specification chain is identical; the document carries the Hiduron name through ordering history.
- Use Nibron Special on UK procurement where the buyer or specifier has a habit of using the Nibron designation. Same alloy, same specification chain, different trade name.
- For dual-name procurement, the purchase order can carry both trade names on the same line with the procurement standard as the binding traceability. EN 10204 type 3.1 or 3.2 certificate carries the chemistry, mechanical and hardness results to the standard, with both trade names referenced in the description field.
Form Availability
Hiduron 191 (and the Nibron Special equivalent) is supplied in the bolting and machined-component 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. Form availability and dimensional range are identical because the underlying alloy class and procurement specification are identical.
Frequently Asked Questions
Q. Is Nibron Special the same alloy as Hiduron 191?
Yes. Both are UNS C72420 Cu-Ni-Mn-Al precipitation-hardened cupronickel qualified under NES 835, DEF STAN 02-835 and DOD-C-24676. The two trade names exist because the alloy class is supplied by parallel UK mill sources under different brand identities; the underlying procurement specifications are identical.
Q. Can I substitute one for the other on a purchase order?
Yes when the purchase order cites the procurement standard (NES 835, DEF STAN 02-835 or DOD-C-24676). The standard is the binding traceability; either trade name fulfils the specification. For sour-service applications the NACE MR0175 hardness ceiling at 286 HBW applies equally.
Q. Are the chemistry and mechanical properties identical?
Yes. Both trade names land in the same chemistry windows (Ni 14 to 15.5 percent, Mn 4 to 5 percent, Al 1.5 to 2.5 percent, Fe 0.5 to 1.5 percent, balance Cu) and the same mechanical floor (Rm 820 to 1000 MPa, Rp0.2 above 580 MPa, A5 above 15 percent, Charpy V above 40 J at RT).
Q. Why do the two trade names exist?
Brand identity. Hiduron is the Langley Alloys brand name and Nibron Special is the Columbia Metals brand name for the same UNS C72420 grade. The naval procurement chain dates the trade-name split back to parallel UK mill development of the Cu-Ni-Mn-Al family for Royal Navy bolting in the same period.
Q. Do you supply both trade names?
TorqBolt supplies the UNS C72420 alloy class to NES 835, DEF STAN 02-835 and DOD-C-24676 with EN 10204 type 3.1 or 3.2 certification. The purchase order can reference either trade name (or both) with the procurement standard as the binding traceability.
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