Approvals & standards
- DEF STAN 02-835 (NES 835)
- DTD 900/4805
- DTD 498
- DOD-C-24676
What these standards mean
DEF STAN 02-835 (NES 835)
The UK Ministry of Defence standard for the high-strength copper-nickel-manganese alloy used in critical naval applications, met by Hiduron® 191. NES 835 is the original Naval Engineering Standard for the same alloy, now carried forward as DEF STAN 02-835.
DTD 900/4805
A UK aerospace and defence material specification for a high-strength copper-nickel-aluminium alloy, met by Hiduron® 130.
DTD 498
A UK Ministry of Defence aerospace specification for a high-strength copper-nickel-silicon alloy, met by Hidurel® 5.
DOD-C-24676
The United States Navy counterpart specification for the high-strength copper-nickel alloy, met by Hiduron® 191.
Why choose Langley
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Built for the naval problem set
Grades chosen to resist seawater and crevice corrosion, hold a low magnetic signature and shrug off hydrogen, all under high cyclic load.
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Non-magnetic where it matters
Options that stay non-magnetic even after machining, for submarine and sensitive-equipment work.
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Full traceability as standard
EN 10204 3.1 certification with every order, and 3.2 third-party inspection on request.
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Approved on demanding supply chains
An approved supplier to Rolls-Royce, registered and certified for defence and aerospace procurement.
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Stock in the UK and the USA
Bar, plate and pipe from stock on both sides of the Atlantic, cut and machined in house.
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Confidentiality assured
We are glad to work under a non-disclosure agreement, holding your specifications, drawings and requirements in confidence.
Defence and naval work sets some of the hardest material problems we see. A component may have to resist seawater and crevice corrosion, keep its magnetic signature low so it does not betray the vessel or interfere with its sensors, survive the hydrogen generated by cathodic protection, and do all of that under high, cyclic load.
Few grades satisfy more than one of those at a time, which is why the naval copper alloys developed for exactly this service are so widely specified.
Hiduron® 191 is approved as a named alloy by leading navies and meets DEF STAN 02-835, NES 835 and DOD-C-24676. It is specified for fasteners for ships and submarines, control elements of submarines, pump shafts, mechanical seals, winch components, gears, hose couplings, weapons handling equipment, components in sonar devices, propeller shafts and drive bushes, valued for its freedom from hydrogen embrittlement and its excellent anti-galling behaviour.
Hiduron® 130 covers subsea hydraulic and electrical connectors, naval winches, seawater valves, submarine control elements, sonar equipment and tow and winch fittings, combining excellent seawater and crevice corrosion resistance with very low magnetic permeability.
Hidurel® 5 is used for naval shafts, bolting for ships and submarines, flanges, swash plate pump components and mine detection equipment, for its bearing and anti-friction behaviour, resistance to hydrogen embrittlement and magnetic permeability below 1.001.
Where the requirement is high strength with a high PREN rather than low magnetism, the super duplex grades Ferralium® 255, Alloy 32760 and Alloy 32750 clear a PREN above 40. Where a component must stay non-magnetic after machining, Fermonic® 50 remains fully non-magnetic even after severe cold work, and Fermonic® 60 is the anti-galling grade for running parts.
We stock this range as bar, plate and pipe in the UK and USA, and machine and cut to size in house where that helps. EN 10204 3.1 certification comes as standard on all material, with 3.2 third party inspection and full traceability, and naval specifications such as DEF STAN and NES supplied where called for. We do not name specific defence programmes or prime contractors in relation to any material we supply.
Platforms & components
- Surface fleet
- Submarines
- Weapons handling
- Sonar
- Propulsion
- Shafting
Selecting alloys by component?
See our naval & submarine fasteners, non-magnetic components and seawater systems application pages for grade selection guidance by component.
Grades
Alloy 2205
UNS S32205Duplex
Alloy 2205 is a 22% chromium duplex stainless steel, stronger and more corrosion-resistant than austenitic grades like 316L.
Alloy 316L
UNS S31603Stainless Steel
Alloy 316L is a low-carbon austenitic stainless steel with molybdenum for improved chloride pitting resistance and easy welding.
Alloy 625
UNS N06625Nickel Alloys
Alloy 625 is a nickel-chromium-molybdenum alloy with excellent corrosion resistance from sub-zero to 980°C and high strength.
Alloy 825
UNS N08825Nickel Alloys
Alloy 825 is a nickel-iron-chromium alloy resisting reducing and oxidising acids and chloride stress-corrosion cracking.
Fermonic® 50
UNS S20910Stainless Steel
Fermonic® 50 is a nitrogen-strengthened austenitic stainless steel with about twice the yield strength of 316.
Fermonic® 60
UNS S21800Stainless Steel
Fermonic® 60 is a nitrogen-strengthened austenitic stainless steel with outstanding galling and wear resistance.
Hidurel® 5
UNS C64700Copper Alloys
Hidurel® 5 is a high-strength copper-silicon-nickel alloy combining seawater corrosion resistance with good machinability.
Hiduron® 130
Hidurax SpecialCopper Alloys
Hiduron® 130 is a high-strength cupronickel supplied in the hot worked condition, combining seawater corrosion resistance, low magnetic permeability and excellent anti-galling properties without any heat treatment. We stock bar in the UK and USA. Plate, tube and fittings are available on enquiry; forgings and castings to order.
Hiduron® 191
DEF STAN 02-835Copper Alloys
Hiduron® 191 is a high-strength copper-nickel alloy with outstanding seawater and biofouling resistance for marine service.
Ferralium® 255
UNS S32550Super Duplex
Ferralium® 255 is a proprietary super duplex stainless steel with high proof stress, PREN over 40 and excellent sub-zero toughness.
Alloy 32750
UNS S32750Super Duplex
Alloy 32750 (2507) is a super duplex stainless steel with PREN over 40, listed in NACE MR0175 for sour service.
Alloy 32760
UNS S32760Super Duplex
Alloy 32760 is a super duplex stainless steel with PREN over 40 and outstanding pitting, crevice and stress-corrosion resistance.
Common questions
Which grades are approved to DEF STAN standards?
Hiduron® 191 meets DEF STAN 02-835 and NES 835. Hiduron® 130 meets DTD 900/4805 and DIN 2.1504. Hidurel® 5 meets DTD 498. Send us the specification your component is called to and we will confirm the matching grade and documentation.
Which grades stay non-magnetic?
Fermonic® 50 remains fully austenitic, and therefore fully non-magnetic, even after severe cold working. The copper alloys Hiduron® 130, Hiduron® 191 and Hidurel® 5 are also virtually non-magnetic, with Hidurel® 5 reaching a magnetic permeability below 1.001, so they cover cases where the part is also immersed in seawater.
Do you supply to naval programmes?
Yes. We supply bar, plate and pipe to naval and defence primes and their subcontractors from stock in the UK and USA, to DEF STAN, NES and other naval specifications where called for. We do not name specific programmes or primes in relation to material we supply.
Material tools
Seawater velocity limits
Seawater Velocity Limits
Check a seawater flow velocity against the maximum design velocity for copper and copper-nickel alloys, to avoid impingement (erosion-corrosion) attack. Enter a velocity directly, or work it out from flow rate and pipe bore. Design guidance from CDA / Nickel Institute and BSMA 18.
| Alloy | UNS | Design velocity | BSMA 18 pipe |
|---|
Design guidance, not a guarantee. Maximum velocities avoid impingement/erosion-corrosion in clean seawater. Limits reduce at small bores (BSMA 18 pipe values apply above ~100 mm bore, reduced below). Local turbulence at bends and fittings, partial blockage, entrained air or sand, and higher temperature all lower the safe velocity. Confirm against the project specification and the product's own data.
PREN calculator
PREN = %Cr + 3.3 × (%Mo + 0.5 × %W) + 16 × %N. Guidance only; always confirm against the grade's datasheet before specifying.
Request a quote
Tell us the grade, form and sizes.
Fast quotes from UK and US stock - bar, plate and pipe, cut and certified to spec.