DTD 900/4805 Hiduron 130

DTD 900/4805 is the UK Air Ministry Directorate of Technical Development specification that governs Hiduron 130 (UNS C72400, Werkstoff 2.1504, CuNi14Al3Fe1) — the mid-strength Cu-Ni-Al precipitation-hardened cupronickel grade for subsea hydraulic connectors, marine bolting and aviation hydraulic components. The specification fixes nickel at 14.0-15.5 percent, aluminium at 2.7-3.4 percent and iron at 1.0-2.0 percent in a copper-balance matrix, with the solution-anneal at 850-900 degrees C followed by gamma-prime age at 475-525 degrees C to develop tensile strength 740-850 MPa and 0.2 percent proof stress above 480 MPa. Magnetic permeability is controlled below 1.005 mu_r, making DTD 900/4805 material acceptable for subsea instrument and naval mine-countermeasures bolting service where magnetic response is a disqualifier. There is no DEF STAN or DOD equivalent for Hiduron 130; DTD 900/4805 is the sole governing procurement document.

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Scope of DTD 900/4805

DTD 900/4805 specifies technical delivery conditions for round bar, forging stock, finished forgings, finished fasteners and machined components in the base Cu-Ni-Al precipitation-hardened cupronickel grade family known as Hiduron 130. The original scope was aviation hydraulics and airframe fittings where the combination of seawater corrosion resistance, anti-galling response and gamma-prime precipitation-hardened mid-strength was required. The grade subsequently became the flagship Cu-Ni-Al alloy for subsea hydraulic and electrical connectors in oil and gas service.

Latest Revision and Sister Standards

DTD 900/4805 is the legacy UK Air Ministry document and remains the primary controlling specification for Hiduron 130 procurement. The grade is dual-referenced to UNS C72400 in the Copper Development Association database and to Werkstoff 2.1504 with chemical-symbol designation CuNi14Al3Fe1 in the German steel-numbers register. There is no separate Defence Standards or US Department of Defense adoption for Hiduron 130; the higher-strength Hiduron 191 grade is the one that carries the NES 835, DEF STAN 02-835 and DOD-C-24676 chain.

Grade Matrix Relevant to Hiduron

Chemistry to DTD 900/4805 (Hiduron 130)

DTD 900/4805 fixes the Hiduron 130 chemistry within tight Cu-Ni-Al-Fe windows. The headline ranges are nickel 14.0 to 15.5 percent, aluminium 2.7 to 3.4 percent, iron 1.0 to 2.0 percent, manganese up to 0.75 percent, balance copper. Tramp limits on lead at 0.02 percent, sulphur and carbon at 0.05 percent maintain hot workability and machinability. The detailed element-by-element table is in the shared Chemistry block below.

Mechanical-Property Floor (DTD 900/4805)

Hiduron 130 in the solution-annealed plus aged condition to DTD 900/4805 holds tensile strength 740 to 850 MPa, 0.2 percent proof stress at least 480 MPa, elongation A5 at least 18 percent, Vickers hardness 240 to 280 HV, and Charpy V impact at least 60 J at room temperature on longitudinal specimens. Magnetic permeability is controlled below 1.005 mu_r for the non-magnetic response that subsea instrument bolting requires. Detailed property table is in the shared Mechanicals block below.

Inspection Categories to EN 10204

DTD 900/4805 supply follows EN 10204 inspection-document categories: type 3.1 mill test certificate issued by the manufacturer with heat-level traceability is the TorqBolt default; type 3.2 inspection certificate with Lloyd's Register, DNV, BV, SGS or TUV witness is supplied on call-out and is standard practice on subsea connector and offshore platform procurement.

Cross-References to Other Standards

DTD 900/4805 cross-references the higher-strength Hiduron 191 grade controlled by NES 835, DEF STAN 02-835 and DOD-C-24676. Where sour-service compliance is required, the grade family steps up to Hiduron 191 with a NACE MR0175 hardness certificate on the same heat. For the side-by-side comparison of the two grades in the family, see the Hiduron 130 vs Hiduron 191 cross-reference page.

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