Stainless Steel ER409Cb
GB ER409Nb
ER409Cb (ER409Nb) is a niobium-stabilized 11% chromium ferritic stainless bare wire, the Nb-stabilized counterpart to Ti-stabilized ER409.
Reference datasheet — ER409Cb 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
ER409Cb tempers and conditions
ER409Cb is supplied in 2 conditions, soft to hard. AW is the default FabDigit quotes; the values on this page are for it.
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Post-weld heat treated | Choose when maximum weld ductility/toughness and stress relief are needed on heavier ferritic sections. | 300 | 450 | 26 | 150 HB | 3 % IACS |
AWDefault As-welded deposit | Standard condition for exhaust and thin-gauge ferritic stainless joints welded and put into service without post-weld heat treatment. | 330 | 480 | 22 | 165 HB | 2.9 % IACS |
Supply forms, finishes and certifications
Ways ER409Cb is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
WIRE-CD | Wire | Supply form |
What is ER409Cb?
ER409Cb (ER409Nb) is a niobium-stabilized 11% chromium ferritic stainless bare wire, the Nb-stabilized counterpart to Ti-stabilized ER409. Niobium stabilization improves weld ductility and arc behaviour, which is why it is used on automotive exhaust components; it is supplied as cold-drawn spooled wire for GTAW and pulsed or short-arc GMAW. Deposits give about 330 MPa yield, 480 MPa tensile, 22% elongation and 165 HB, with service to 675 °C. Corrosion resistance stays modest (score 45) and grain coarsening still limits heat input; ER409 is the cheaper option where the extra weld ductility is not needed. ER409Cb 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). ER409Cb has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 480 MPa (69.6 ksi) — weaker than 57% of stainless steel grades. Elongation at break is 22% and the elastic modulus is 200 GPa (29 Msi).
What is ER409Cb used for?
- Automotive exhaust component welding
- Muffler and resonator shell seams
- Catalytic converter and downpipe joints
- 409-grade tube and flange welds
- Heat shields and exhaust brackets
- Flue and vent sheet fabrication
Advantages
- Easy to machine — 55/100, better than 94% of stainless steel grades
- Low embodied carbon — 3.4 kg CO₂/kg, better than 91% of stainless steel grades
- Conducts heat well — 24.9 W/m·K (14.4 BTU/hr·ft·°F), better than 87% of stainless steel grades
- High electrical conductivity — 2.9 % IACS, better than 87% of stainless steel grades
- Readily welded — 80/100, better than 80% of stainless steel grades
Limitations
- Low fracture toughness — 45 MPa·√m (41 ksi·√in), worse than 95% 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
ER409Cb properties
Typical room-temperature values for ER409Cb-AW; bars are the position among stainless steel grades.
Physical3
ER409Cb 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
ER409Cb has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 480 MPa (69.6 ksi) — weaker than 57% of stainless steel grades. Elongation at break is 22% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
ER409Cb is rated for continuous service to 675°C (1,247 °F). It conducts heat at 24.9 W/m·K (14.4 BTU/hr·ft·°F), better than 87% of stainless steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
ER409Cb 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 ER409Cb takes about 45 MJ of energy and emits 3.4 kg of CO₂ — less than 91% of stainless steel grades. Typical recycled content is 60%.
Manufacturability6
ER409Cb's machinability is good (55/100, better than 94% of stainless steel grades); weldability very good (80/100); formability fair (45/100).
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. ER409Cb is highlighted; hover a dot for its name, or open the interactive family chart.
Working with ER409Cb
Is ER409Cb easy to machine?
Weld metal machines like Type 409 ferritic stainless — use sharp carbide, positive rake and generous feed to avoid work-hardened smearing; expect gummy chips.
Can ER409Cb be welded?
Use GTAW or short-arc/pulsed GMAW with Ar or Ar+2%CO₂, low heat input and interpass ≤150 °C to limit ferrite grain coarsening; no preheat needed on thin gauge, 100–200 °C preheat on sections >10 mm.
Can ER409Cb be formed, bent or molded?
Supplied as cold-drawn wire; keep spool clean and dry, and avoid tight de-reeling radii that cause feedability problems or wire kinking.
ER409Cb 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 |
|---|---|---|
| CAWS A5.9 max | ≤ 0.08 | 0.03 |
| Cr | 10.5 – 13.5 | 12 |
| Ni | ≤ 0.6 | 0.25 |
| NbNb+Ta; stabilizer | 0.5 – 1.5 | 0.9 |
| Mn | ≤ 0.8 | 0.5 |
| Si | ≤ 1 | 0.5 |
| Tiresidual only in Nb-stabilized type | ≤ 0.15 | |
| Cu | ≤ 0.75 | |
| P | ≤ 0.04 | |
| S | ≤ 0.03 | |
| Fe | balance |
What surface finishes work on ER409Cb?
Pickle/passivate or wire-brush with stainless-only tools after welding to restore the passive film; weld metal takes paint and aluminized coatings well but will surface-rust if scale is left on.
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 ER409Cb in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- GB (China)
- ER409Nb
How much does ER409Cb cost?
ER409Cb 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.
ER409Cb — frequently asked
What is ER409Cb used for?
ER409Cb is typically used for automotive exhaust component welding, muffler and resonator shell seams, catalytic converter and downpipe joints, 409-grade tube and flange welds, heat shields and exhaust brackets and flue and vent sheet fabrication. In short: nb-stabilized 409 filler; better weld ductility than ER409; exhaust-grade ferritic wire.
What is the yield strength of ER409Cb?
ER409Cb has a typical yield strength of 330 MPa (47.9 ksi) and a tensile strength of 480 MPa (69.6 ksi) — weaker than 57% of stainless steel grades. Strength varies by condition: see the 2 listed tempers.
Is ER409Cb easy to machine?
Reasonably — machinability is rated good (55/100, better than 94% of stainless steel grades). Weld metal machines like Type 409 ferritic stainless — use sharp carbide, positive rake and generous feed to avoid work-hardened smearing; expect gummy chips.
Can ER409Cb be welded?
Yes — weldability is rated very good (80/100). Use GTAW or short-arc/pulsed GMAW with Ar or Ar+2%CO₂, low heat input and interpass ≤150 °C to limit ferrite grain coarsening; no preheat needed on thin gauge, 100–200 °C preheat on sections >10 mm.
What surface finishes work on ER409Cb?
Pickle/passivate or wire-brush with stainless-only tools after welding to restore the passive film; weld metal takes paint and aluminized coatings well but will surface-rust if scale is left on.
Can ER409Cb be formed, bent or molded?
Supplied as cold-drawn wire; keep spool clean and dry, and avoid tight de-reeling radii that cause feedability problems or wire kinking.
What is the maximum service temperature of ER409Cb?
ER409Cb 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.
How much does ER409Cb cost?
ER409Cb 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 A5.9/A5.9M — Bare Stainless Steel Welding Electrodes and Rods — AWS (2017)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.6 — Welding, Brazing, and Soldering (ferritic stainless welding) — ASM International (1993)
- Stainless ferritic filler metal datasheets (ER409Cb/ER409Nb) — 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.