Stainless Steel SUS429J1 1/4H
Supply condition
JIS SUS429J1
1/4H = quarter hard
Use when extra stiffness/springback and higher yield are needed in flat or roll-formed parts; forming ductility reduced.
Values for the 1/4H condition
What is SUS429J1 1/4H?
SUS429J1 1/4H is SUS429J1 supplied in the 1/4H condition — use when extra stiffness/springback and higher yield are needed in flat or roll-formed parts; forming ductility reduced. SUS429J1 1/4H has a yield strength of 460 MPa (66.7 ksi) and a tensile strength of 580 MPa (84.1 ksi) — stronger than 73% of stainless steel grades. Elongation at break is 13% and the elastic modulus is 200 GPa (29 Msi). SUS429J1 1/4H has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,425°C (2,597 °F).
Advantages
- Easy to machine — 55/100, better than 94% of stainless steel grades
- Conducts heat well — 25 W/m·K (14.4 BTU/hr·ft·°F), better than 93% of stainless steel grades
- High electrical conductivity — 2.9 % IACS, better than 87% of stainless steel grades
- High service temperature — 815°C (1,499 °F), better than 77% of stainless steel grades
Limitations
- Limited ductility — 13%, worse than 93% of stainless steel grades
- Needs corrosion protection — 48/100, worse than 80% of stainless steel grades
SUS429J1 1/4H properties
Typical room-temperature values for SUS429J1 1/4H; 6 are specific to this condition. Other listed values are SUS429J1 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
SUS429J1 1/4H has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,425°C (2,597 °F).
Mechanical14
SUS429J1 1/4H has a yield strength of 460 MPa (66.7 ksi) and a tensile strength of 580 MPa (84.1 ksi) — stronger than 73% of stainless steel grades. Elongation at break is 13% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
SUS429J1 1/4H is rated for continuous service to 815°C (1,499 °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 10.4 µm/m·K (5.78 µin/in·°F).
Electrical3
SUS429J1 1/4H conducts electricity at 2.9 % IACS, better than 87% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (48/100), worse than 80% of stainless steel grades.
Sustainability4
Producing a kilogram of SUS429J1 1/4H takes about 52 MJ of energy and emits 4.2 kg of CO₂ — less than 76% of stainless steel grades. Typical recycled content is 65%.
Manufacturability7
SUS429J1 1/4H's machinability is good (55/100, better than 94% of stainless steel grades); weldability good (55/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with SUS429J1 1/4H
Is SUS429J1 easy to machine?
Machines more freely than austenitic stainless (~55 % of 1212); use sharp positive-rake carbide, rigid setup and generous coolant to avoid built-up edge and work-hardened skin.
Can SUS429J1 be welded?
Weldable by GTAW/laser/HF-ERW with low heat input; HAZ grain growth and 475 °C embrittlement risk — use 430/309 or Nb-stabilised filler and avoid preheat above ~150 °C, post-weld anneal for best ductility.
Can SUS429J1 be formed, bent or molded?
Good deep-drawing and roll-forming behaviour with modest springback; watch ridging/roping in drawn panels and keep bend radius ≥1t transverse to rolling direction.
What surface finishes work on SUS429J1?
Passivate or electropolish after pickling to restore the Cr-rich film; not anodizable — PVD colouring, painting or brushed/BA mill finishes are the usual routes.
SUS429J1 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 |
|---|---|---|
| CJIS G4305 max | ≤ 0.12 | 0.06 |
| Si | ≤ 1 | 0.5 |
| Mn | ≤ 1 | 0.6 |
| P | ≤ 0.04 | 0.03 |
| S | ≤ 0.03 | 0.01 |
| Niresidual/permitted | ≤ 0.6 | 0.25 |
| Cr | 15 – 17 | 16 |
| Cudeliberate addition distinguishing J1 from plain SUS429 | 0.3 – 0.8 | 0.5 |
| Monot specified by JIS; some mill variants add ~0.3–0.5 % Mo for exhaust-condensate corrosion resistance — confirm on mill certificate | — | |
| Fe | balance |
SUS429J1 1/4H — frequently asked
What is SUS429J1 1/4H used for?
SUS429J1 1/4H is typically used for exhaust manifolds, catalytic converter housings, heat shields and flex pipe components. In short: mo-modified 429 for exhaust; 815 °C oxidation resistance; nickel-free exhaust stainless.
What is the yield strength of SUS429J1 1/4H?
SUS429J1 1/4H has a typical yield strength of 460 MPa (66.7 ksi) and a tensile strength of 580 MPa (84.1 ksi) — stronger than 73% of stainless steel grades.
Is SUS429J1 1/4H easy to machine?
Reasonably — machinability is rated good (55/100, better than 94% of stainless steel grades). Machines more freely than austenitic stainless (~55 % of 1212); use sharp positive-rake carbide, rigid setup and generous coolant to avoid built-up edge and work-hardened skin.
Can SUS429J1 1/4H be welded?
Yes — weldability is rated good (55/100). Weldable by GTAW/laser/HF-ERW with low heat input; HAZ grain growth and 475 °C embrittlement risk — use 430/309 or Nb-stabilised filler and avoid preheat above ~150 °C, post-weld anneal for best ductility.
What surface finishes work on SUS429J1 1/4H?
Passivate or electropolish after pickling to restore the Cr-rich film; not anodizable — PVD colouring, painting or brushed/BA mill finishes are the usual routes.
Can SUS429J1 1/4H be formed, bent or molded?
Good deep-drawing and roll-forming behaviour with modest springback; watch ridging/roping in drawn panels and keep bend radius ≥1t transverse to rolling direction.
What is the maximum service temperature of SUS429J1 1/4H?
SUS429J1 1/4H is rated for continuous use to about 815°C (1,499 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- JIS G4305 Cold-rolled stainless steel plate, sheet and strip — JSA (2021)
- JIS G4304 Hot-rolled stainless steel plate, sheet and strip — JSA (2021)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys (ferritic stainless) — ASM International (1990)
- Machinery's Handbook — machinability ratings for stainless steels — Industrial Press (2020)
- Ferritic stainless steels for automotive exhaust systems — Nippon Steel Stainless / JFE (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.