Project Description
436 (UNS S43600 / 1.4526) Stainless Steel Seamless Tube
Grade 436 ferritic stainless steel is a molybdenum- and niobium-stabilized chromium alloy that delivers a measurable step up in corrosion resistance from standard Type 430, without the nickel-driven cost volatility of austenitic grades. The molybdenum addition improves pitting resistance in mild chloride and condensate environments, while niobium stabilization locks carbon into stable carbides, effectively reducing sensitization risk during welding and high-temperature service. Supplied as seamless tube by Fushun Steel Tube, UNS S43600 (EN 1.4526 / X6CrMoNb17-1) performs reliably in automotive exhaust systems, heat exchangers, boiler components, and industrial ducting where thermal cycling, oxidation, and moderate corrosion are everyday conditions. Its ferritic microstructure remains magnetic in all conditions and provides low thermal expansion, a practical advantage in assemblies that experience repeated heating and cooling.
Fushun Steel Tube manufactures 436 stainless steel seamless tube from 6 mm to 610 mm outside diameter with wall thicknesses from 1 mm to 100 mm, covering the size ranges called for by ASTM A268, EN 10297-2, and equivalent international standards. Each heat is produced through our EAF + LF + VD steelmaking route, with optional ESR remelting available for applications demanding the highest cleanliness levels. Whether you need standard stock sizes or custom non-standard dimensions, contact us for a free quote with your tube specifications.
Product Overview
Below is a representative image of 436 stainless steel seamless tubes in as-supplied condition. Fushun Steel Tube delivers tubes with surface finishes ranging from hot-rolled and annealed-pickled to cold-drawn bright, depending on your application requirements.
Applications
Grade 436 stainless steel tube is specified across industries where moderate corrosion resistance, thermal stability, and cost control are equally important. Its nickel-free chemistry keeps material costs predictable, while its ferritic structure provides the dimensional stability designers need for close-tolerance assemblies.
- Automotive exhaust manifolds and downpipes — Withstands repeated thermal cycling and exhaust gas condensate without sensitization
- Catalytic converter housings and heat shields — Strong scaling resistance up to approximately 850°C
- Boiler superheater and reheater tubes — Performs in high-temperature steam and flue gas environments
- Heat exchanger tube bundles — Used in condensing boilers, waste heat recovery units, and hot gas ducting
- Burner components and furnace parts — Oxidation resistance under cyclic heating conditions
- Food processing equipment — Hot water tanks, steam cooking lines, and heating plates where nickel-free material is preferred
- Home appliance components — Oven interiors, range hood ducting, electric water heater elements
- Industrial exhaust ducting and flue gas piping — Corrosion resistance in mildly acidic condensate environments
For applications that demand even higher pitting resistance, consider our stainless steel tube range in duplex or super-austenitic grades. If your application involves precisely controlled dimensions with tight tolerances, our cold-drawn steel tube capability can supply 436 in bright annealed condition. Tell us your specifications and our engineering team will recommend the optimal grade and delivery condition.
Specifications & Standards
Grade 436 stainless steel is covered by multiple international standards for seamless and welded tube products. The table below summarizes the key standards applicable to this grade across different delivery forms and end-use conditions.
| Standard | Scope | Product Form | Grade Designation |
|---|---|---|---|
| ASTM A268 / A268M | Seamless and welded ferritic stainless steel tubing for general service | Seamless & welded tube | TP436 / UNS S43600 |
| ASTM A240 / A240M | Chromium and chromium-nickel stainless steel plate, sheet, and strip | Flat products (reference) | 436 / UNS S43600 |
| ASME SA-268 | Seamless and welded ferritic stainless steel tubing (ASME Boiler & Pressure Vessel Code) | Seamless & welded tube | TP436 / UNS S43600 |
| EN 10297-2 | Seamless circular steel tubes for mechanical and general engineering — stainless steel | Seamless tube | X6CrMoNb17-1 / 1.4526 |
| EN 10296-2 | Welded circular steel tubes for mechanical and general engineering — stainless steel | Welded tube | X6CrMoNb17-1 / 1.4526 |
| EN 10216-5 | Seamless steel tubes for pressure purposes — stainless steel | Seamless pressure tube | X6CrMoNb17-1 / 1.4526 |
| EN 10088-2 | Stainless steels — sheet/plate and strip for general purposes (reference) | Flat products (reference) | X6CrMoNb17-1 / 1.4526 |
| EN 10088-3 | Stainless steels — semi-finished products, bars, rods, and sections (reference) | Long products (reference) | X6CrMoNb17-1 / 1.4526 |
| JIS G3463 | Stainless steel boiler and heat exchanger tubes | Seamless & welded tube | SUS436L / SUS436LTB |
| JIS G3446 | Stainless steel tubes for machine and structural purposes | Seamless & welded tube | SUS436 |
| GB/T 14976 | Seamless stainless steel tubes for fluid transport | Seamless tube | 12Cr17MoNb |
Fushun Steel Tube supplies 436 seamless tubes certified to the standard required by your project. When ordering, specify the governing standard, dimensions, quantity, and any supplementary testing requirements. For pressure equipment under the European Pressure Equipment Directive (PED), we can provide EN 10216-5 certified tubes with full traceability.
Available Sizes & Delivery
| Parameter | Seamless Hot-Rolled | Seamless Cold-Drawn / Cold-Rolled |
|---|---|---|
| Outside Diameter (OD) | 26.7 mm – 610 mm | 6 mm – 168 mm |
| Wall Thickness (WT) | 2.5 mm – 100 mm | 1 mm – 25 mm |
| Length | Fixed 5.8 m / 6 m, or random length up to 12 m | Fixed lengths 3 m – 12 m |
| Surface Finish | Hot-rolled, annealed and pickled | Cold-drawn bright (2B), annealed and pickled |
- Ready Stock Delivery
- Common sizes of 436 seamless tube in stock ship within approximately 7 days from order confirmation.
- Custom / Non-Standard Orders
- Minimum order quantity: 2–3 tons. Typical delivery: 25–35 days from drawing approval, depending on the steelmaking and pipe-making schedule.
- Small Trial Orders
- Accepted for grade qualification and first-article testing. Our mill regularly accommodates small-batch production runs for new project development.
- Volume Orders
- Competitive pricing and flexible delivery scheduling available for annual contracts and large-quantity inquiries. Contact us for volume pricing.
Chemical Composition
The chemical composition of 436 stainless steel is defined under multiple standards. The table below compares the ladle analysis requirements per ASTM A240, EN 10088-2, and GB/T 3280. The key differentiating elements are molybdenum for pitting resistance and niobium for stabilization against intergranular corrosion.
| Element | ASTM A240 (UNS S43600) | EN 10088-2 (1.4526 / X6CrMoNb17-1) | GB/T 3280 (12Cr17MoNb) |
|---|---|---|---|
| Carbon (C) | ≤ 0.12 | ≤ 0.08 | ≤ 0.08 |
| Silicon (Si) | ≤ 1.00 | ≤ 1.00 | ≤ 1.00 |
| Manganese (Mn) | ≤ 1.00 | ≤ 1.00 | ≤ 1.00 |
| Phosphorus (P) | ≤ 0.040 | ≤ 0.040 | ≤ 0.040 |
| Sulfur (S) | ≤ 0.030 | ≤ 0.015 | ≤ 0.015 |
| Chromium (Cr) | 16.0 – 18.0 | 16.0 – 18.0 | 16.0 – 18.0 |
| Molybdenum (Mo) | 0.75 – 1.25 | 0.8 – 1.4 | 0.50 – 1.00 |
| Niobium (Nb) | 5 × C min, 0.80 max | 0.20 – 0.80 (*) | 0.20 – 0.80 |
| Nitrogen (N) | — | ≤ 0.040 | — |
| Iron (Fe) | Balance | ||
(*) Under EN 10088-2, niobium content may also be calculated per the stabilization formula: Nb = [7 × (C + N) + 0.1] to 1.00. The values shown are the nominal range.
The EN specification imposes tighter limits on carbon (0.08% max vs. 0.12% in ASTM A240) and sulfur (0.015% vs. 0.030%), reflecting European pressure-equipment expectations. For tube orders governed by EN 10216-5, the EN 10088-2 composition shall apply. Fushun Steel Tube routinely achieves carbon levels well below the maximum through careful EAF + LF + VD processing, producing heats with consistently low residual elements.
Manufacturing Process
Fushun Steel Tube produces 436 stainless steel seamless tube through an integrated steelmaking and pipe-making route that ensures full traceability from raw material to finished product. The process begins in our electric arc furnace (EAF), where carefully selected scrap and ferroalloys are melted under oxidizing conditions. The molten steel is transferred to a ladle furnace (LF) for precise alloy trimming and desulfurization, followed by vacuum degassing (VD) to reduce dissolved gases — particularly hydrogen and nitrogen — to levels that support clean microstructure and consistent mechanical properties.
For applications requiring the highest cleanliness or specific solidification patterns, we offer electroslag remelting (ESR) as an optional upgrade. The refined ingot or continuous-cast billet is then hot-pierced and hot-rolled on our Assel or pilger mill to produce the mother tube, which can be further cold-drawn or cold-rolled to achieve tighter dimensional tolerances and brighter surface finishes. Our cold-drawn tube capability supports OD ranges from 6 mm to 168 mm with wall thicknesses as low as 1 mm. Every tube lot undergoes final annealing — typically at 780–830°C followed by air cooling or water quenching — to restore the ferritic microstructure and relieve forming stresses.
Mechanical Properties
The mechanical properties of 436 stainless steel tube depend on the delivery condition and the governing standard. The values below represent typical minimum requirements for the annealed condition, as referenced by ASTM A268 and EN 10297-2. Actual properties from Fushun Steel Tube production heats routinely exceed these minimums.
| Property | Symbol | Typical Range | ASTM A268 (min.) | EN 10297-2 (min.) (*) |
|---|---|---|---|---|
| Tensile Strength | Rm | 450 – 600 MPa | 415 MPa | 480 – 680 MPa |
| Yield Strength (0.2% offset) | Rp0.2 | 250 – 350 MPa | 205 MPa | 280 MPa |
| Elongation (longitudinal) | A | 20 – 32% | 20% | 20% |
| Hardness | HBW / HRB | ≤ 200 HBW / ≤ 89 HRB | ≤ 89 HRB | ≤ 200 HBW |
| Elastic Modulus | E | 200 GPa | — | |
(*) EN values are typical for X6CrMoNb17-1 (1.4526) under the relevant tube standard. Tensile and yield values may vary with wall thickness; verify against the purchase specification.
Note that 436 is a ferritic stainless steel and cannot be hardened by heat treatment. Its strength derives from solid-solution strengthening by chromium and molybdenum, plus grain refinement through controlled hot-working and cold-drawing practices. The ductility of this grade supports bending, flaring, and flattening operations commonly required during tube installation.
Heat Treatment
Ferritic stainless steels like 436 undergo annealing as their primary thermal treatment. Unlike martensitic grades, 436 cannot be hardened by quenching. The annealing process recrystallizes the cold-worked structure, relieves residual stresses from forming, and restores optimum corrosion resistance. Fushun Steel Tube applies controlled atmosphere or bright annealing for cold-drawn tubes where surface integrity matters.
| Treatment | Temperature Range | Holding Time | Cooling Method | Purpose |
|---|---|---|---|---|
| Full Annealing | 780 – 850 °C | 30 min per 25 mm of wall thickness | Air cool or water quench | Recrystallize structure, restore ductility and corrosion resistance |
| Bright Annealing | 780 – 830 °C | As above, in protective atmosphere | Rapid cool in hydrogen or dissociated ammonia | Produce bright, scale-free surface for cold-drawn tubes |
| Stress Relieving | 200 – 350 °C | 1 – 2 hours | Air cool | Relieve residual stresses from cold working or welding without altering microstructure |
For welded tube fabrication, post-weld annealing at the full annealing temperature range is recommended for critical service to restore corrosion resistance in the heat-affected zone. However, the niobium stabilization inherent to 436 significantly reduces the risk of sensitization even in the as-welded condition, making it more forgiving than unstabilized ferritic grades during on-site welding operations.
Surface Finish & Tolerances
Fushun Steel Tube supplies 436 stainless steel seamless tube in several surface conditions, selectable based on the end-use requirements. Hot-rolled tubes are delivered in the annealed and pickled condition with a matte, scale-free surface suitable for general industrial and heat-exchanger applications. For applications demanding tighter dimensional control and a smoother bore, our cold-drawn and cold-rolled tube capability delivers a bright (2B) surface finish with enhanced dimensional accuracy.
Dimensional tolerances follow the applicable tube standard: ASTM A268 for general service tubes, EN 10216-5 for pressure equipment, or customer-specified tighter limits when required. For cold-drawn tubes, we routinely achieve OD tolerances of ±0.08 mm and wall thickness tolerances of ±10% (better on request). Internal surface roughness can be specified down to Ra ≤ 3.2 μm for applications where fluid flow characteristics or cleanliness matter. Our cold-rolled tube line extends precision further for the tightest tolerance bands. Request a sample to verify surface quality against your specification.
Quality Assurance & Testing
Every lot of 436 stainless steel seamless tube shipped by Fushun Steel Tube passes through a comprehensive quality control workflow designed to verify conformance to the purchase specification before release. Our ISO 9001 certified quality management system underpins every stage.
- Raw Material Inspection — Incoming billet or ingot is verified by optical emission spectrometry (OES) for full chemical composition against the specified grade. Only heats meeting all element limits proceed to pipe-making.
- In-Process Checks — During hot rolling and cold drawing, dimensional checks (OD, WT, length, straightness) are performed at each process step. Surface condition is visually inspected and, for critical orders, supplemented by dye penetrant testing.
- Finished Product Testing — Each tube undergoes:
- Hydrostatic test or eddy current / ultrasonic NDT per the governing standard to verify soundness
- Tensile testing at room temperature for yield strength, tensile strength, and elongation
- Hardness testing (Brinell or Rockwell B)
- Flattening test or flaring test to confirm ductility
- Intergranular corrosion test per EN ISO 3651-2 (for EN-grade orders) or ASTM A262 Practice E
- Dimensional final inspection — OD, WT, length, straightness, and end squareness
- Metallographic Examination — Microstructure verification on a per-heat basis confirms fully ferritic grain structure free of detrimental phases.
- Certification — All test results are compiled into an EN 10204 Type 3.1 inspection certificate (Type 3.2 with third-party witnessing available on request), providing full traceability from heat number to final tube.
Supplementary testing — including elevated-temperature tensile, creep rupture, or corrosion testing in specific media — can be arranged at the time of order.
Packing & Shipping
All 436 stainless steel tubes are packed to prevent mechanical damage, moisture ingress, and contamination during transit. Small-diameter cold-drawn tubes are bundled with plastic end caps and wrapped in waterproof kraft paper before being placed in seaworthy wooden cases. Larger-diameter hot-rolled tubes are secured in hexagonal bundles with steel strapping, with wooden dunnage separating each layer. For export shipments, we apply vapor-phase corrosion inhibitor (VCI) paper and desiccant packs inside fully enclosed crates.
We ship from Hunan Province, China, via major ports (Shanghai, Ningbo, Shenzhen) to destinations worldwide. Standard shipping methods include sea freight (FCL / LCL), air freight for urgent orders, and rail freight for overland destinations. Each shipment is accompanied by the full documentation package: commercial invoice, packing list, bill of lading or airway bill, and material test certificates. For time-sensitive projects, we can coordinate expedited logistics with tracking visibility from dispatch to delivery.
Frequently Asked Questions
- What is the difference between 436 and 430 stainless steel tube?
- 436 contains molybdenum (0.75–1.25%) and is niobium-stabilized, giving it better pitting resistance and weld zone corrosion performance than 430, which has neither molybdenum nor stabilization. For applications involving mild chlorides, condensate, or welding in the field, 436 is the preferred upgrade.
- Can 436 stainless steel tube be used for pressure equipment under PED?
- Yes. X6CrMoNb17-1 (1.4526) is listed in EN 10216-5, the harmonized European standard for stainless steel pressure tubes. Fushun Steel Tube can supply 436 seamless pressure tubes with EN 10204 3.1 certification suitable for PED Category I–IV equipment, subject to notified-body involvement where required by the category.
- What is the maximum OD and wall thickness you can supply in 436 seamless?
- Our hot-rolled seamless capability covers OD up to 610 mm with wall thickness up to 100 mm. For larger diameters, please inquire — we can evaluate alternative manufacturing routes including hot-expanded seamless.
- Does 436 stainless steel tube require post-weld heat treatment?
- Not always. The niobium stabilization in 436 significantly reduces sensitization risk, and many non-critical welded assemblies perform satisfactorily in the as-welded condition. For service in corrosive media or pressure equipment, post-weld annealing at 780–830°C is recommended to fully restore corrosion resistance in the heat-affected zone.
- How does 436 compare with 304 stainless steel for cost and performance?
- 436 is nickel-free, making it more cost-stable than 304 (which contains 8–10.5% nickel). In moderate corrosion environments — automotive exhaust, heat exchangers, hot water — 436 performs comparably to 304. However, for severe chloride exposure or cryogenic service, austenitic grades like 304 or 316 remain the better choice. Contact us for a free quote and we can help you evaluate the most cost-effective grade for your application.
