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Standards & Designations

A guide to the numbering systems behind every spec chip on Langley grade pages - who issues them, what they govern - and a searchable cross-reference of all 60 designations to their Langley alloy.

Articles Documents Standards Glossary

60 results

Designation Cross-Reference

60 designations from 17 grades. Click any row to open its explanation. Filter by system or material family, or search by designation, alloy name, or standard number.

UNS S17400 is the designation for 17-4 PH, a precipitation-hardening martensitic stainless steel offering high strength and moderate corrosion resistance in a single heat treatment. It is used for shafts, valve and pump components and general high-strength stainless parts.

System: UNS Used on: 17-4 PH

Werkstoff 1.4542 is the European material number for 17-4 PH precipitation-hardening stainless steel (S17400). It provides high strength and moderate corrosion resistance from a single precipitation-hardening heat treatment.

System: EN / Werkstoff Used on: 17-4 PH

AMS 5643 is the SAE aerospace specification for 17-4 PH precipitation-hardening stainless steel (UNS S17400) as bar, wire, forgings and rings. It covers the alloy across its various age-hardened conditions for high-strength stainless aerospace and industrial components.

System: AMS Used on: 17-4 PH

ASTM A564 Type 630 (AISI 630) is the specification for hot- and cold-finished precipitation-hardening stainless steel bar - the designation for 17-4 PH. It covers the alloy in its solution-treated and various aged conditions for high-strength stainless components.

System: ASTM Used on: 17-4 PH

ASTM A564 Type 630 (AISI 630) is the specification for hot- and cold-finished precipitation-hardening stainless steel bar - the designation for 17-4 PH. It covers the alloy in its solution-treated and various aged conditions for high-strength stainless components.

System: AISI Used on: 17-4 PH

UNS S32205 is the current designation for 2205 duplex stainless steel, a dual-phase austenitic-ferritic alloy with roughly twice the strength of standard austenitics and excellent resistance to chloride pitting and stress-corrosion cracking. It is used widely in oil and gas, chemical and marine service.

System: UNS Used on: Alloy 2205

UNS S31803 is an earlier designation for 2205 duplex stainless steel, a balanced austenitic-ferritic alloy combining high strength with strong resistance to chloride pitting and stress-corrosion cracking. Most current material is specified to the tightened S32205 range.

System: UNS Used on: Alloy 2205
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Werkstoff 1.4462 is the European material number for 2205 duplex stainless steel, a dual-phase alloy with high strength and strong resistance to chloride pitting and stress-corrosion cracking. It is the standard workhorse duplex grade.

System: EN / Werkstoff Used on: Alloy 2205
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UNS S31603 is the designation for Type 316L, the low-carbon molybdenum-bearing austenitic stainless steel. The reduced carbon minimises sensitisation after welding, giving reliable corrosion resistance in chloride and mildly acidic service across marine, chemical and food-processing use.

System: UNS Used on: Alloy 316L

Werkstoff 1.4404 is the European material number for Type 316L, the low-carbon molybdenum-bearing austenitic stainless steel. The low carbon resists sensitisation after welding, giving dependable corrosion resistance in chloride and mildly acidic service.

System: EN / Werkstoff Used on: Alloy 316L

ASTM A276 is the standard specification for stainless steel bars and shapes, covering hot- and cold-finished bar in a wide range of austenitic, martensitic and other grades. Condition A refers to material supplied solution-annealed. It sets dimensions, mechanical requirements and testing for general stainless bar.

System: ASTM Used on: Alloy 316L , Fermonic® 50 , Fermonic® 60
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ASTM A479 is the standard specification for stainless steel bars and shapes for use in boilers and other pressure vessels. It sets the requirements for hot- and cold-finished bar across austenitic, duplex and high-strength grades, covering dimensions, mechanical testing and certification.

System: ASTM Used on: Alloy 316L , Fermonic® 50 , Fermonic® 60
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UNS S32750 is the designation for 25% chromium super duplex stainless steel (the 2507 type), offering very high strength and PREN above 40 for severe chloride service. It is specified across oil and gas, marine, desalination and chemical processing.

System: UNS Used on: Alloy 32750

Werkstoff 1.4410 is the European material number for 25% chromium super duplex stainless steel (the 2507 / S32750 type), offering very high strength and PREN above 40 for severe chloride and sour service.

System: EN / Werkstoff Used on: Alloy 32750
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UNS S32760 is the designation for a tungsten- and copper-bearing 25% chromium super duplex stainless steel. It delivers very high strength with outstanding resistance to pitting and crevice corrosion in seawater and sour service.

System: UNS Used on: Alloy 32760

Werkstoff 1.4501 is the European material number for the tungsten- and copper-bearing super duplex stainless steel (S32760 type). It combines very high strength with outstanding pitting and crevice-corrosion resistance in seawater service.

System: EN / Werkstoff Used on: Alloy 32760
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UNS N06625 is the designation for nickel Alloy 625, a nickel-chromium-molybdenum-niobium alloy known for outstanding resistance to pitting, crevice and general corrosion across a very wide temperature range. It is supplied for marine, chemical-processing, aerospace and subsea service.

System: UNS Used on: Alloy 625
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Werkstoff 2.4856 is the European material number for nickel Alloy 625 (UNS N06625), the nickel-chromium-molybdenum-niobium alloy prized for wide-ranging corrosion resistance and elevated-temperature strength.

System: EN / Werkstoff Used on: Alloy 625
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AMS 5666 is the SAE aerospace specification for nickel Alloy 625 (UNS N06625) bar, rod, forgings and rings in the annealed condition. It is specified where the corrosion resistance and elevated-temperature strength of Alloy 625 are required in aerospace and high-integrity industrial parts.

System: AMS Used on: Alloy 625
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ASTM B446 is the standard specification for nickel Alloy 625 (and related) rod, bar and wire. It defines the chemical, mechanical and dimensional requirements for solid-section Alloy 625 product.

System: ASTM Used on: Alloy 625

BS 3076 is the British Standard for nickel and nickel-alloy bar (part of the BS 3071-3076 series covering nickel-alloy product forms). Alloy-specific 'NA' numbers identify the grade - NA16 is Alloy 825, NA18 is Monel K-500 - and Langley supplies Alloy 625 to BS 3076.

System: BS Used on: Alloy 625

UNS N07718 is the Unified Numbering System designation for nickel Alloy 718, an age-hardenable nickel-chromium alloy strengthened by niobium and combining high strength with good corrosion resistance from cryogenic temperatures to around 700C. It is one of the most widely specified superalloys for aero-engine, gas-turbine and high-integrity oil and gas components.

System: UNS Used on: Alloy 718
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Werkstoff 2.4668 is the European material number for nickel Alloy 718 (UNS N07718), the age-hardenable nickel-chromium superalloy combining high strength with good corrosion resistance across a wide temperature range.

System: EN / Werkstoff Used on: Alloy 718
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ASTM B637 is the standard specification for precipitation-hardenable and cold-worked nickel-alloy bars, forgings and forging stock for high-temperature service, covering grades such as Alloy 718 and Alloy 725. It is specified where age-hardened nickel-alloy strength is required.

System: ASTM Used on: Alloy 718

AMS 5662 is the SAE aerospace specification covering nickel Alloy 718 (UNS N07718) as bar, forging stock and rings in the solution-treated condition. This is the softer, more machinable state; components are normally age-hardened afterwards, often to AMS 5663, to reach full strength. It is specified for jet-engine, gas-turbine and high-integrity oil and gas parts.

System: AMS Used on: Alloy 718

AMS 5663 is the age-hardened counterpart to AMS 5662: the same Alloy 718 bar, forging stock and rings, but supplied solution-treated and precipitation-hardened to full strength, ready to use. It is specified where maximum tensile, fatigue and creep performance matters, typically rotating and structural aerospace components and demanding downhole hardware.

System: AMS Used on: Alloy 718

UNS N07725 is the designation for nickel Alloy 725, an age-hardenable nickel-chromium-molybdenum-niobium alloy that combines very high strength with the corrosion resistance of Alloy 625. It is widely specified for oil and gas downhole tools, fasteners and subsea hardware in sour, high-chloride service.

System: UNS Used on: Alloy 725
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ASTM B805 is the standard specification for precipitation-hardening nickel-alloy bar and wire, covering grades such as Alloy 725 and Alloy 925. It defines requirements for these high-strength corrosion-resistant alloys, widely used in oilfield downhole and subsea hardware.

System: ASTM Used on: Alloy 725 , Alloy 925

UNS N08825 is the designation for nickel Alloy 825, a nickel-iron-chromium alloy with molybdenum and copper for resistance to both reducing and oxidising acids and to chloride stress-corrosion cracking. It is common in chemical processing, pickling plant and pollution-control equipment.

System: UNS Used on: Alloy 825
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Werkstoff 2.4858 is the European material number for nickel Alloy 825 (UNS N08825), a nickel-iron-chromium alloy with molybdenum and copper for resistance to both reducing and oxidising acids. It is common in chemical processing and pickling plant.

System: EN / Werkstoff Used on: Alloy 825
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ASTM B425 is the standard specification for nickel Alloy 825 (UNS N08825) rod and bar. It sets the composition, mechanical properties and testing for solid-section Alloy 825 used in corrosion-resistant service.

System: ASTM Used on: Alloy 825

BS 3076 is the British Standard for nickel and nickel-alloy bar (part of the BS 3071-3076 series covering nickel-alloy product forms). Alloy-specific 'NA' numbers identify the grade - NA16 is Alloy 825, NA18 is Monel K-500 - and Langley supplies Alloy 625 to BS 3076.

System: BS Used on: Alloy 825

UNS N09925 is the designation for nickel Alloy 925, an age-hardenable nickel-iron-chromium alloy that adds high strength to the corrosion resistance of Alloy 825. It is used for oil and gas production hardware such as hangers, valves and fasteners in sour environments.

System: UNS Used on: Alloy 925
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UNS N05500 is the designation for Monel K-500, an age-hardenable nickel-copper alloy that combines the corrosion resistance of Monel 400 with substantially higher strength and hardness. It is specified for marine shafting, pump and valve parts and fasteners.

System: UNS Used on: Alloy K-500
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Werkstoff 2.4375 is the European material number for Monel K-500 (UNS N05500), the age-hardenable nickel-copper alloy offering marine corrosion resistance with high strength.

System: EN / Werkstoff Used on: Alloy K-500
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BS 3076 is the British Standard for nickel and nickel-alloy bar (part of the BS 3071-3076 series covering nickel-alloy product forms). Alloy-specific 'NA' numbers identify the grade - NA16 is Alloy 825, NA18 is Monel K-500 - and Langley supplies Alloy 625 to BS 3076.

System: BS Used on: Alloy K-500

AMS 4676 is the SAE aerospace material specification for Monel K-500 (UNS N05500) bar and forgings, hot-finished and precipitation-hardenable. It is specified where the marine corrosion resistance of the nickel-copper system is combined with high strength, for shafting, fasteners and pump and valve parts.

System: AMS Used on: Alloy K-500

DIN 17743 is the German standard covering wrought nickel-copper alloys (the Monel family). It defines composition and property requirements for these corrosion-resistant nickel-copper materials.

System: EN / Werkstoff Used on: Alloy K-500

UNS S20910 is the designation for the high-strength nitrogen-strengthened austenitic stainless steel supplied by Langley as Fermonic 50 (also known as Nitronic 50 / XM-19). It offers roughly twice the yield strength of 316/316L with superior pitting and crevice-corrosion resistance, and is used for fasteners, pump and valve parts and marine hardware.

System: UNS Used on: Fermonic® 50
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XM-19 is the ASTM designation for the high-strength nitrogen-strengthened austenitic stainless steel supplied by Langley as Fermonic 50 (also UNS S20910 / Nitronic 50). It offers around twice the yield strength of 316/316L with superior pitting and crevice-corrosion resistance.

System: ASTM Used on: Fermonic® 50

Werkstoff 1.3964 (X2CrNiMoNbN23-17) is the European material number for the high-nitrogen high-strength austenitic stainless steel supplied by Langley as Fermonic 50 (S20910 / XM-19). It offers high strength with good pitting and crevice-corrosion resistance.

System: EN / Werkstoff Used on: Fermonic® 50

UNS S21800 is the designation for the galling- and wear-resistant austenitic stainless steel supplied by Langley as Fermonic 60 (Nitronic 60). Its high strength and self-mating anti-galling behaviour suit valve stems, bushings, fasteners and wear components.

System: UNS Used on: Fermonic® 60
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UNS S32550 is the designation for the super duplex stainless steel supplied by Langley as Ferralium 255. It combines high strength with excellent resistance to pitting, crevice corrosion and stress-corrosion cracking in aggressive chloride environments.

System: UNS Used on: Ferralium® 255
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UNS S32520 is a designation covering the super duplex stainless steel supplied by Langley as Ferralium 255. Super duplex grades offer very high strength and PREN above 40 for demanding chloride and sour service in oil and gas, marine and desalination applications.

System: UNS Used on: Ferralium® 255
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Werkstoff 1.4507 is the European material number for the super duplex stainless steel supplied by Langley as Ferralium 255 (S32550). EN 10088-3 is the standard for stainless bar. It offers high strength with excellent resistance to chloride pitting and stress-corrosion cracking.

System: EN / Werkstoff Used on: Ferralium® 255
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ASME Code Case 1883, with allowable stresses given in Table UHA-23, is the ASME Boiler and Pressure Vessel Code acceptance under which super duplex Ferralium 255 (S32550) may be used in code-stamped pressure-vessel construction.

System: ASME Used on: Ferralium® 255

UNS C64700 is the designation for the precipitation-hardening copper-nickel-silicon alloy supplied by Langley as Hidurel 5. It combines high strength with high electrical and thermal conductivity, and is used for electrical, marine and engineering components.

System: UNS Used on: Hidurel® 5

CuNi2Si (EN designation CW111C) is the copper-nickel-silicon alloy supplied by Langley as Hidurel 5, a precipitation-hardening copper alloy combining high strength with high electrical and thermal conductivity.

System: EN / Werkstoff Used on: Hidurel® 5

ASTM B411 is the standard specification for copper-nickel-silicon rod and bar; grade C64700 is Langley's Hidurel 5. It sets the chemical, mechanical and dimensional requirements for this high-strength, high-conductivity copper alloy.

System: ASTM Used on: Hidurel® 5

BS 4577 (Type A3/2) is a British Standard for copper alloy met by Langley's Hidurel 5 copper-nickel-silicon alloy.

System: BS Used on: Hidurel® 5

BS 2B25 is a British aerospace standard for copper-alloy bar met by Langley's Hidurel 5.

System: BS Used on: Hidurel® 5

DTD 498 is a UK aerospace material specification (Directorate of Technical Development) met by Langley's Hidurel 5 copper-nickel-silicon alloy.

System: Other Used on: Hidurel® 5

MSRR 8501 is a Rolls-Royce Material Specification Requirement met by Langley's Hidurel 5 copper-nickel-silicon alloy.

System: Other Used on: Hidurel® 5

CuNi2Si (EN designation CW111C) is the copper-nickel-silicon alloy supplied by Langley as Hidurel 5, a precipitation-hardening copper alloy combining high strength with high electrical and thermal conductivity.

System: EN / Werkstoff Used on: Hidurel® 5

DIN material number 2.1504 is a German designation met by the high-strength cupronickel supplied by Langley as Hiduron 130.

System: EN / Werkstoff Used on: Hiduron® 130
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DTD 900/4805 is a UK aerospace material specification met by Langley's Hiduron 130 high-strength cupronickel.

System: Other Used on: Hiduron® 130

DEF STAN 02-835 (formerly Naval Engineering Standard NES 835) is the UK naval material standard met by Langley's Hiduron 191, a high-strength cupronickel used for marine and submarine components.

System: Other Used on: Hiduron® 191
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DEF STAN 02-835 (formerly Naval Engineering Standard NES 835) is the UK naval material standard met by Langley's Hiduron 191, a high-strength cupronickel used for marine and submarine components.

System: Other Used on: Hiduron® 191
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Designation Systems

These systems give an alloy its identity - the number or code that names it, regardless of who stocks it or what form it takes.

UNS Unified Numbering System

Jointly maintained by ASTM International and SAE International. Provides a single, unambiguous alphanumeric identifier for each metal alloy. A UNS number is a letter followed by five digits - the letter indicates the alloy family: S = stainless and heat-resisting steels; N = nickel and nickel alloys; C = copper and copper alloys. The digits are often derived from legacy designation numbers. UNS does not specify product form, temper, or heat treatment - it names the alloy composition only.

W.Nr. / EN Werkstoff-Nr. & European Standard

The German Werkstoff-Nummer (material number) system, maintained under DIN (Deutsches Institut für Normung), uses a four-decimal number to identify alloys. The European Norm (EN) designation system is aligned with DIN for most alloys and the numbers are interchangeable. The leading digit indicates family: 1.4xxx = stainless and heat-resisting steel; 2.4xxx = nickel alloy; 2.0xxx / 2.1xxx = copper alloy. Some chips on Langley grade pages show the bare number (e.g. 1.4410) without the "EN" prefix; the standard is the same.

AMS SAE Aerospace Material Specifications

Published by SAE International. AMS specifications define composition, processing, testing, and minimum property requirements for alloys and other materials used in aerospace and high-performance applications. A single alloy may carry multiple AMS numbers for different product forms or heat-treatment conditions - for example, AMS 5662 and AMS 5663 both cover Alloy 718 bar, differing in required heat treatment. Where a grade page shows an AMS number, the alloy has been qualified to that specification and can be supplied with the corresponding test certification.

ASTM ASTM International

Published by ASTM International. ASTM standards specify composition, mechanical properties, dimensions, and testing for specific product forms. The designation includes a letter and number - A = ferrous, B = non-ferrous - followed by a standard number, sometimes with a grade, type, or class suffix. The same alloy appears in multiple ASTM standards depending on form: ASTM A276 and A479 both cover bar for stainless alloys, but differ in scope and property requirements. XM-19 is a supplementary ASTM designation for a high-nitrogen austenitic steel.

BS British Standards

Published by BSI Group (British Standards Institution). BS alloy designations remain in use for heritage materials, naval, and defence specifications, though many have been superseded by or aligned with EN standards. The BS 3072-3076 series covers wrought nickel and nickel-alloy products, with NA-prefixed grades within those standards (NA16 = Alloy 825; NA18 = Alloy K-500). Other BS numbers (BS 2B25, BS 4577) cover aerospace and specialist copper alloys.

AISI American Iron and Steel Institute

Legacy US designation system for stainless and tool steels. AISI designations (e.g. AISI 630, AISI 316L) are widely recognised commercially but are not governed by a formal standards body in the same way as UNS or ASTM - they originated as trade designations for common alloy groups. AISI 630 is the legacy name for 17-4 PH stainless steel (UNS S17400). AISI designations have largely been superseded by UNS for formal specification purposes but remain in widespread commercial use.

ASME ASME Code Cases

Published by the American Society of Mechanical Engineers. ASME Code Cases permit specific materials or construction methods for use in pressure vessel and piping design under the ASME Boiler and Pressure Vessel Code (BPVC), before or in lieu of formal code inclusion. ASME Code Case 1883 allows Ferralium 255 (UNS S32550) to be used in ASME-governed pressure equipment. Code Cases are referenced in purchase orders to specify the allowable basis.

Other UK aerospace, defence & specialist specs

DTD (Directorate of Technical Development) - historic UK Ministry of Aviation material specifications now withdrawn but still referenced in legacy aerospace supply chains. DEF STAN (Defence Standard) - UK MoD material and engineering specifications; DEF STAN 02-835 for Hiduron 191 superseded the earlier NES 835 (Naval Engineering Standard) reference. MSRR (Rolls-Royce Aerospace material specifications) - Rolls-Royce internal specifications for aerospace components; MSRR 8501 covers the CuNiSi alloy used in aerospace bearings and bushings. CW / CuNi - EN wrought copper alloy designations (CW prefix, e.g. CW111C) and EN compositional shorthand (CuNi2Si = copper with nominal 2% nickel, silicon addition). J93373 - ASTM cast alloy designation for Ferralium 255 in cast form (ASTM A890).

Service & Qualification Standards

These standards qualify an alloy for a specific service condition - they do not name or identify it. An alloy listed under NACE MR0175 meets defined resistance criteria; the NACE number is not its designation. The table below shows which Langley grades are listed under each qualification standard.

NORSOK MDS D45

NORSOK M-650

NORSOK MDS D57