Stainless Steel E409Nb
UNS W40910
E409Nb is a niobium-stabilized ferritic stainless electrode (W40910, E409Nb-16 to GB/T 983) that matches Type 409 base metal, with the niobium addition tying up carbon to resist intergranular corrosion in the weld zone.
Reference datasheet — E409Nb is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the AW condition
E409Nb tempers and conditions
E409Nb is supplied in 5 conditions, soft to hard. AW is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Post-weld heat treated | Choose when maximum weld-metal ductility, toughness and dimensional stability are needed on thicker sections. | 330 | 470 | 26 | 160 HB | 3 % IACS |
E409Nb-17 | Pick for the finest bead appearance and fluid slag on flat/horizontal fillets in sheet-metal exhaust work. | 375 | 495 | 22 | 176 HB | 2.9 % IACS |
AWDefault As-welded deposit | Standard condition for thin-gauge exhaust and automotive fabrication where no PWHT is applied. | 380 | 500 | 22 | 180 HB | 2.9 % IACS |
E409Nb-16 | Most widely stocked coating type: smooth arc, easy slag removal, all-position on thin exhaust sheet with AC or DC+ power sources. | 380 | 500 | 22 | 180 HB | 2.9 % IACS |
E409Nb-15 | Use where lowest hydrogen and best weld-metal toughness/crack resistance are required on restrained or thicker joints. | 390 | 505 | 23 | 183 HB | 2.9 % IACS |
What is E409Nb?
E409Nb is a niobium-stabilized ferritic stainless electrode (W40910, E409Nb-16 to GB/T 983) that matches Type 409 base metal, with the niobium addition tying up carbon to resist intergranular corrosion in the weld zone. It is chosen for low-cost thin-gauge exhaust and mild-service sheet fabrication and is supplied in -15, -16 and -17 coatings, with as-welded and PWHT deposit data on file. All-weld metal runs about 380 MPa yield, 500 MPa tensile and 22 % elongation, with service to 675 °C. Corrosion resistance is limited (score 45) and the ferritic deposit has low notch ductility at room temperature; use E430Nb where higher chromium is required. E409Nb has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,480°C (2,696 °F). E409Nb has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 500 MPa (72.5 ksi) — stronger than 52% of stainless steel grades. Elongation at break is 22% and the elastic modulus is 200 GPa (29 Msi).
What is E409Nb used for?
- Automotive exhaust systems
- Mufflers and catalytic converter shells
- Heat exchanger tubing repair
- Mild corrosive service parts
Advantages
- Conducts heat well — 25 W/m·K (14.4 BTU/hr·ft·°F), better than 93% of stainless steel grades
- Easy to machine — 48/100, better than 88% of stainless steel grades
- High electrical conductivity — 2.9 % IACS, better than 87% of stainless steel grades
- Low embodied carbon — 3.8 kg CO₂/kg, better than 77% of stainless steel grades
Limitations
- Low fracture toughness — 40 MPa·√m (36.4 ksi·√in), worse than 97% of stainless steel grades
- Hard to polish — 55/100, worse than 89% of stainless steel grades
- Needs corrosion protection — 45/100, worse than 85% of stainless steel grades
- Limited ductility — 22%, worse than 75% of stainless steel grades
E409Nb properties
Typical room-temperature values for E409Nb-AW; bars are the position among stainless steel grades.
Physical3
E409Nb has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,480°C (2,696 °F).
Mechanical16
E409Nb has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 500 MPa (72.5 ksi) — stronger than 52% of stainless steel grades. Elongation at break is 22% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
E409Nb is rated for continuous service to 675°C (1,247 °F). It conducts heat at 25 W/m·K (14.4 BTU/hr·ft·°F), better than 93% of stainless steel grades. Thermal expansion is 11 µm/m·K (6.11 µin/in·°F).
Electrical3
E409Nb conducts electricity at 2.9 % IACS, better than 87% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 85% of stainless steel grades.
Sustainability4
Producing a kilogram of E409Nb takes about 52 MJ of energy and emits 3.8 kg of CO₂ — less than 76% of stainless steel grades. Typical recycled content is 65%.
Manufacturability6
E409Nb's machinability is fair (48/100, better than 88% of stainless steel grades); weldability very good (70/100); formability fair (35/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. E409Nb is highlighted; hover a dot for its name, or open the interactive family chart.
Working with E409Nb
Is E409Nb easy to machine?
Weld deposit machines like Type 409 — moderate rating (~55% of AISI 1212); use sharp carbide, rigid setup and positive rake to avoid work-hardened smearing.
Can E409Nb be welded?
Redry electrodes per maker's schedule, use low heat input and stringer beads, interpass below ~150 °C to limit ferrite grain coarsening; 150–250 °C preheat helps on thick or restrained sections.
Can E409Nb be formed, bent or molded?
Deposit is fully ferritic with limited ductility — avoid tight-radius cold forming across the weld; form the sheet before welding where possible.
E409Nb chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| C | ≤ 0.12 | 0.06 |
| Cr | 11 – 14 | 12.5 |
| Ni | ≤ 0.6 | 0.3 |
| Mn | ≤ 1 | 0.6 |
| Si | ≤ 1 | 0.6 |
| Nbcolumbium, stabilizer | 0.5 – 1.5 | 0.9 |
| Mo | ≤ 0.75 | |
| Cu | ≤ 0.75 | |
| P | ≤ 0.04 | |
| S | ≤ 0.03 | |
| Fe | balance |
What surface finishes work on E409Nb?
Grind and pickle/passivate to restore the chromium oxide film; the deposit takes a fair mechanical polish but will rust-stain if free iron or heat tint remains.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel E409Nb in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- W40910
- Also called
- AWS A5.4 E409Nb-XX
How much does E409Nb cost?
E409Nb is a premium-cost stainless steel ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
E409Nb — frequently asked
What is E409Nb used for?
E409Nb is typically used for automotive exhaust systems, mufflers and catalytic converter shells, heat exchanger tubing repair and mild corrosive service parts. In short: low-cost exhaust-grade filler; stabilized against weld decay; ferritic, limited weld ductility.
What is the yield strength of E409Nb?
E409Nb has a typical yield strength of 380 MPa (55.1 ksi) and a tensile strength of 500 MPa (72.5 ksi) — stronger than 52% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is E409Nb easy to machine?
Reasonably — machinability is rated fair (48/100, better than 88% of stainless steel grades). Weld deposit machines like Type 409 — moderate rating (~55% of AISI 1212); use sharp carbide, rigid setup and positive rake to avoid work-hardened smearing.
Can E409Nb be welded?
Yes — weldability is rated very good (70/100). Redry electrodes per maker's schedule, use low heat input and stringer beads, interpass below ~150 °C to limit ferrite grain coarsening; 150–250 °C preheat helps on thick or restrained sections.
What surface finishes work on E409Nb?
Grind and pickle/passivate to restore the chromium oxide film; the deposit takes a fair mechanical polish but will rust-stain if free iron or heat tint remains.
Can E409Nb be formed, bent or molded?
Deposit is fully ferritic with limited ductility — avoid tight-radius cold forming across the weld; form the sheet before welding where possible.
What is the maximum service temperature of E409Nb?
E409Nb is rated for continuous use to about 675°C (1,247 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between E409Nb-AW and E409Nb PWHT?
AW is the default condition — standard condition for thin-gauge exhaust and automotive fabrication where no PWHT is applied. PWHT: choose when maximum weld-metal ductility, toughness and dimensional stability are needed on thicker sections. Yield strength is 380 MPa in AW versus 330 MPa in PWHT.
How much does E409Nb cost?
E409Nb is a premium-cost stainless steel ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- AWS A5.4/A5.4M — Stainless Steel Electrodes for Shielded Metal Arc Welding — American Welding Society (2012)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys (Type 409) — ASM International (1990)
- ASM Handbook Vol.6 — Welding, Brazing and Soldering (ferritic stainless weldability) — ASM International (1993)
- Ferritic stainless SMAW electrode datasheets (409/409Nb class) — Welding consumable producers (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.