AMS 5536 is the SAE Aerospace Material Specification governing Hastelloy X (UNS N06002 / DIN 2.4665) in flat-rolled forms - sheet, strip, and plate - supplied in the solution-annealed condition. The full title reads: "Nickel Alloy, Corrosion and Heat-Resistant, Sheet, Strip, and Plate, 47Ni-22Cr-18Fe-9Mo, Solution Annealed."
Product Forms
Bar & Rod
Plate & Sheet
Coil & Strip
Pipe & Tube
Fitting: Flange, Tee, Elbow, Reducer etc.
Forging: Ring, Shaft, Circle, Block etc.
The Chemistry Behind AMS 5536
Hastelloy X is a solid-solution-strengthened nickel-chromium-iron-molybdenum alloy. Unlike precipitation-hardened superalloys (think Inconel 718 or Waspaloy), it does not rely on gamma-prime precipitates for strength. That makes it easier to weld and form, but it also means its high-temperature capability comes from a different mechanism - solid-solution stiffening and in-service carbide precipitation.
AMS 5536 Chemical Composition Limits
| Element | Min (%) | Max (%) | Why It's There |
|---|---|---|---|
| Nickel (Ni) | Balance (~47%) | - | Austenitic matrix; fundamental high-temperature stability |
| Chromium (Cr) | 20.50 | 23.00 | Forms Cr₂O₃ protective oxide layer; oxidation and hot corrosion resistance |
| Iron (Fe) | 17.00 | 20.00 | Reduces cost; improves rolling mill response; contributes to spinel subscale |
| Molybdenum (Mo) | 8.00 | 10.00 | Solid-solution strengthening; creep resistance at 700–980°C |
| Cobalt (Co) | 0.50 | 2.50 | Additional solid-solution strengthening; synergistic with Mo and W |
| Tungsten (W) | 0.20 | 1.00 | Works alongside Mo for high-temperature creep strength |
| Carbon (C) | 0.05 | 0.15 | Forms M₆C and M₂₃C₆ carbides at grain boundaries during service; pins boundaries against creep sliding |
| Silicon (Si) | - | 1.00 | Aids oxidation resistance; deoxidizer during melting |
| Manganese (Mn) | - | 1.00 | Controls sulfur; improves hot workability |
| Phosphorus (P) | - | 0.040 | Impurity - kept low to avoid embrittlement |
| Sulfur (S) | - | 0.030 | Impurity - kept low to avoid hot shortness |
| Boron (B) | - | 0.010 | Trace grain boundary strengthening element |
Mechanical Properties: What to Verify on Every MTR
AMS 5536 requires the material to meet specific mechanical property minimums in the solution-annealed condition. The solution anneal is performed at 1163°C ±14°C (2125°F ±25°F), followed by rapid cooling. Here is what the spec demands:
| Property | AMS 5536 Minimum | Test Standard | Notes |
|---|---|---|---|
| Ultimate Tensile Strength (UTS) | 690 MPa (100 ksi) | ASTM E8 | Transverse or longitudinal; spec does not mandate orientation |
| 0.2% Yield Strength | 276 MPa (40 ksi) | ASTM E8 | Lower than some data sheets show - check actual vs. spec minimum |
| Elongation in 2" (50 mm) | 35% | ASTM E8 | Reflects the alloy's excellent ductility in annealed condition |
| Grain Size (sheet < 1.27 mm) | ASTM 5 or finer | ASTM E112 | Only required for thin gauge sheet; coarse grain causes orange-peel during forming |
| Hardness (if specified) | 96 HRB max | ASTM E18 | Verification test - not always required by the PO |
One discrepancy you will notice across supplier data sheets: some quote UTS minimums of 655 MPa (95 ksi) and yield of 240 MPa (35 ksi). Those numbers come from ASTM B435, not AMS 5536. The AMS spec is slightly more demanding. If your MTR shows values barely meeting the ASTM minimums, the material may have been certified to B435 and then "upgraded" in the paperwork - a red flag worth investigating.
Elevated Temperature Performance
Room-temperature properties tell you the material was correctly annealed, but they do not predict service performance. What matters in application is how the alloy holds up at operating temperature. Hastelloy X under AMS 5536 maintains useful strength up to about 816°C (1500°F) under structural load, and provides oxidation resistance up to 1204°C (2200°F) in non-load-bearing or low-stress configurations.
| Temperature | 0.2% Yield (MPa) | UTS (MPa) | Elongation (%) |
|---|---|---|---|
| Room temp (21°C / 70°F) | 324 | 720 | 46 |
| 538°C / 1000°F | 286 | 648 | 45 |
| 649°C / 1200°F | 272 | 472 | 37 |
| 760°C / 1400°F | 261 | 435 | 37 |
| 871°C / 1600°F | 177 | 252 | 51 |
Notice how elongation actually increases at 871°C. That is not a typo - the material becomes more ductile at extreme temperatures, which is one reason it resists thermal fatigue cracking in combustor applications. The strength drop-off above 800°C is real, though, and that is where design engineers must rely on creep-rupture data rather than short-time tensile values.
Product Forms and Dimensional Boundaries
AMS 5536 defines three flat-rolled product forms with specific thickness boundaries. Getting these wrong on a purchase order is one of the most common mistakes we see from buyers who are new to nickel alloy procurement.
| Product Form | Thickness Range | Width Range | Typical Use |
|---|---|---|---|
| Sheet | 0.10 mm – 4.76 mm (0.004" – 0.187") | Any width | Combustor liners, formed components, stamped parts |
| Strip | < 4.76 mm thick AND < 305 mm wide | Up to 304 mm | Precision components, sealing rings, welded tube feedstock |
| Plate | > 4.76 mm (> 0.187") | Any width | Structural brackets, flanges, heavy-wall fabrication |
The distinction between sheet and strip is not semantic. Strip is a narrower product, typically slit from wider coil, and it carries different tolerance expectations. If you order "sheet" but what you actually need is slit-to-width strip with tight edge conditions, your supplier needs to know that upfront. Slitting introduces edge burr and work-hardening at the cut edge, which can cause problems in downstream stamping or deep drawing.
For plate, thickness tolerances per AMS 2242 are tighter than commercial mill tolerances. If you are buying plate for a machined component where wall thickness is critical, specify AMS 2242 tolerance class on the PO - otherwise you may receive material at the minus tolerance limit that does not clean up during machining.
AMS 5536 vs ASTM B435 vs ASME SB435: The Specification Triangle
Three specifications cover the same UNS N06002 alloy in flat-rolled form. Understanding the differences prevents both over-specification (paying for documentation you do not need) and under-specification (failing an audit or an incoming inspection).
| Specification | Governing Body | Product Form | Key Difference |
|---|---|---|---|
| AMS 5536 | SAE International | Sheet, strip, plate | Aerospace grade; full documentation chain, lot testing, grain size, AMS 2242 tolerances |
| ASTM B435 | ASTM International | Sheet, strip, plate | General industrial grade; chemistry and mechanicals, less stringent documentation |
| ASME SB435 | ASME (Boiler & Pressure Vessel Code) | Sheet, strip, plate | ASTM B435 adopted into ASME Code for pressure vessel applications; required for Code-stamped fabrication |
In practice: if you are fabricating a pressure vessel for a European customer that needs a CE mark under the Pressure Equipment Directive (PED 2014/68/EU), ASME SB435 (or the equivalent EN material standard) is what your Notified Body will want to see. If you are supplying components for a gas turbine program where the prime contractor is GE or Siemens, AMS 5536 is almost certainly the callout. If you are building industrial furnace muffles for a heat-treat shop, ASTM B435 is fine and will save you 15–25% on material cost.
Where AMS 5536 Material Actually Ends Up in Service
Understanding the end-use application helps you anticipate what your customer cares about and what documentation they will scrutinize most closely.
Aerospace and Gas Turbine Engines
The single largest consumer of AMS 5536 sheet is the gas turbine industry - both aerospace engines and land-based power generation turbines. Specific components include:
- Combustor cans and combustion liners (the hottest section of the engine)
- Transition ducts connecting the combustor to the turbine section
- Flame holders and spray bars
- Afterburner components in military engines
- Exhaust nozzles and tailpipe structures
- Turbine seals and static ring segments
For these applications, the material faces sustained temperatures of 800–1100°C in an oxidizing combustion gas environment, with thermal cycling on every startup and shutdown. The combination of oxidation resistance, creep strength, and fabricability (you can deep-draw combustor cans from it) is what makes Hastelloy X the default choice.
Industrial Heat Treatment Equipment
Furnace rolls, retorts, muffles, radiant tubes, heat-treat baskets, and fixtures. These components run continuously at 900–1200°C in oxidizing, reducing, or neutral atmospheres. AMS 5536 plate is common for structural furnace components where the higher documentation chain provides traceability for insurance and safety audits.
Petrochemical and Refining
Catalyst support grids in reforming furnaces, pigtails and manifolds in ethylene cracking units, flash dryer components, and high-temperature reaction vessels. In refining service, the alloy's resistance to carburization and nitriding - two failure modes that destroy stainless steel in petrochemical furnaces - is the primary value driver.
Power Generation
Land-based gas turbine combustor components, heat recovery steam generator internals, boiler components in advanced power cycles, and recuperator foils in microturbine systems.
Fabrication and Welding: What Happens After the Material Arrives
AMS 5536 material is supplied in the solution-annealed condition, which means it is relatively soft and ductile - ready for forming, welding, and machining. But nickel alloys behave differently from stainless steel, and fabricators who are used to 304 or 316L often run into problems.
Forming
Hastelloy X work-hardens rapidly - faster than austenitic stainless steel. A bend radius that works for 316L may cause cracking in Hastelloy X. For complex deep-drawn parts, plan for one or two intermediate anneals (rapid cooling from 1150–1175°C) to restore ductility. Use lubricants specifically formulated for nickel alloys; standard stainless steel forming lubricants may not provide adequate performance.
Welding
Hastelloy X has excellent weldability for a superalloy. It can be joined using GTAW (TIG), GMAW (MIG), and SMAW. Key points:
- Use matching filler metal (ERNiCrMo-2 / AMS 5798) for most applications. For dissimilar welds to stainless steel, ERNiCr-3 or ERNiCrMo-3 may be used.
- No preheat is required. In fact, preheating nickel alloys can be counterproductive - it increases the risk of hot cracking.
- Control interpass temperature. Keep it below 150°C for most applications.
- Post-weld heat treatment is generally not required, but a full solution anneal after heavy welding can restore maximum ductility and corrosion resistance.
- Minimize heat input. Nickel alloys have low thermal conductivity, so heat concentrates in the weld zone. Lower amperage and faster travel speeds help prevent distortion and carbide precipitation in the heat-affected zone.
Machining
Hastelloy X machines like other nickel alloys - which is to say, it is challenging. Expect tool life to be 30–50% shorter than for 316L stainless. Use sharp carbide tools, positive rake angles, moderate cutting speeds, and generous coolant flow. Rigidity is critical - minimize tool overhang and use rigid workholding to prevent chatter, which causes work-hardening and rapid tool failure.
Cutting
Plasma cutting, laser cutting, and waterjet cutting are all viable. Plasma cutting is the most economical for thicker plate, but be aware that the heat-affected zone may develop a thin hardened layer that should be removed by grinding before welding. Waterjet cutting produces no heat-affected zone and is preferred for thin sheet where edge quality is critical.
Pricing Factors: What Drives the Cost of AMS 5536 Material
Nickel alloy pricing is volatile and depends on factors that change monthly, sometimes weekly. Here is what actually drives the price you pay for AMS 5536 sheet, strip, or plate.
Raw Material Indices
The London Metal Exchange (LME) nickel price is the single largest cost driver. Nickel constitutes roughly 47% of the alloy by weight, so a 10% move in LME nickel translates to approximately a 5% move in material cost. Chromium, molybdenum, and cobalt prices also contribute. Most mills quote with a raw material surcharge that adjusts monthly based on published indices.
Specification and Documentation Level
AMS 5536 material costs 15–30% more than ASTM B435 material for the same size and quantity, purely because of the additional testing, documentation, and quality system overhead. EN 10204 3.2 certificates add another 3–8% compared to 3.1, because of the third-party inspector's involvement.
Quantity and Size
Small orders (under 100 kg) carry a significant premium - often 40–60% above large-quantity pricing. Standard mill sizes (1000 × 2000 mm, 1220 × 2440 mm, 1500 × 3000 mm sheet; 2000 × 6000 mm plate) are more economical than custom-cut sizes. For strip, standard coil widths (100 mm, 150 mm, 200 mm, 300 mm) are cheaper than custom slit widths.
Frequently Asked Questions
What is the maximum service temperature for AMS 5536 material?
For structural load-bearing applications, AMS 5536 Hastelloy X retains useful strength up to approximately 816°C (1500°F). For oxidation resistance without significant mechanical load - for example, a furnace muffle supported externally - the alloy performs up to 1204°C (2200°F). The practical limit depends on stress level, atmosphere composition, and expected service life. For long-term creep-limited applications (10,000+ hours), most designs cap the temperature at 870–980°C.
Is AMS 5536 magnetic?
No. Hastelloy X is non-magnetic in both the solution-annealed and lightly cold-worked conditions. This is relevant for applications near sensitive electronic or magnetic equipment, and it also means PMI verification cannot use magnetic sorting - you need XRF or OES equipment.
Can AMS 5536 sheet be used for seawater service?
It can, but it is not the optimal choice. Hastelloy X was designed for high-temperature dry corrosion resistance, not wet chloride service. For seawater or wet chloride environments, Hastelloy C-276, C-22, or Inconel 625 are better choices. If your application involves both high temperature and occasional seawater exposure (for example, offshore gas turbine components), Hastelloy X is acceptable but should be protected from sustained wet chloride contact.
What is the difference between AMS 5536 and AMS 5754?
AMS 5536 covers sheet, strip, and plate. AMS 5754 covers bar, rod, and wire - in the same UNS N06002 alloy and the same solution-annealed condition. The mechanical property requirements differ slightly because bar and rod are tested differently (often in longitudinal orientation) and have different grain size expectations. If you need both flat-rolled and bar stock for the same project, order both to their respective AMS specifications.
How do I verify that my supplier's AMS 5536 certificate is genuine?
Three steps: (1) Contact the mill listed on the MTR and verify the heat number directly. (2) Perform PMI testing at receiving to confirm the alloy chemistry matches the certificate. (3) For high-value or safety-critical material, commission an independent third-party laboratory to perform a full chemical analysis and mechanical test on a sample. If any of these checks fail, quarantine the material and initiate a supplier corrective action request.
What is the DIN equivalent of AMS 5536?
The DIN designation is 2.4665, and the EN designation is NiCr22Fe18Mo9. The European equivalent specification for flat-rolled product is EN 10095 (heat-resistant steels and nickel alloys) or ASTM B435 / ASME SB435, depending on the application. Note that DIN 2.4665 refers to the alloy itself, not the product form specification - so a material certified to DIN 2.4665 may or may not meet all AMS 5536 requirements without additional documentation.
What welding filler should I use with AMS 5536 material?
For most applications, use matching filler wire: ERNiCrMo-2 (also covered by AMS 5798). This maintains composition consistency between the base metal and weld deposit. For dissimilar welds to carbon steel or stainless steel, ERNiCr-3 (Inconel 82) or ERNiCrMo-3 (Inconel 625) filler are commonly used. Always consult the welding procedure specification (WPS) qualified for your specific application.
What is the minimum order quantity for AMS 5536 material?
This varies by supplier and product form. For stock material, many suppliers will sell cut-to-size pieces with no minimum. For mill-direct orders of non-stock material, the minimum is typically 200–500 kg for sheet and strip, and 500–1000 kg for plate. Small-quantity orders from stock carry a cutting and handling premium of 20–50%.
