AISI 429 Stainless Steel Plate | A240 Type 429 | UNS S42900
What is AISI 429 Stainless Steel?
As a professional China steel mill-Direct Supply and stainless steel plate supplier, SHH STEEL is pleased to present AISI 429 Stainless Steel Plate.
AISI 429 is widely known and searched under many different names and designations, including AISI 429, ASTM A240 Type 429, ASME SA240 Type 429, UNS S42900, 429 stainless steel, 429 stainless steel plate, SUS429 and 14–16% Cr ferritic 429. All these names refer to the same intermediate-chromium ferritic stainless steel.
AISI 429 contains 14.0–16.0% chromium with carbon limited to 0.12%. Chromium is higher than in A240 410 or A240 410S, so atmospheric and mild chemical resistance is better. Chromium is lower than in A240 430, so AISI 429 is often selected as a cost-effective ferritic option when full 16–18% Cr is not required.
The grade is magnetic, non-hardenable by conventional quench and temper, and normally supplied annealed. It is used for welded fabrications, nitric-acid related equipment, tanks, automotive parts and general industrial plate where moderate corrosion resistance and good formability are needed.
SHH STEEL supplies AISI 429 as true China steel mill-Direct Supply, sourcing directly from major Chinese stainless steel mills. This model delivers competitive mill pricing, consistent quality, complete heat traceability and reliable delivery.
AISI 429 is frequently compared with A240 410, A240 410S, A240 430, A240 409, A240 439 and A240 434. SHH STEEL provides technical support to help customers choose the most appropriate 400-series grade.
Material Specification
| Specification Element | Requirement | SHH STEEL Compliance |
|---|---|---|
| Grade | AISI 429 / A240 Type 429 / UNS S42900 | Confirmed |
| Related Standards | ASTM A240, ASME SA240, JIS (SUS429) | Available |
| Product Form | Plate, Sheet | Available |
| Delivery Condition | Annealed | Standard |
| Thickness Range | 0.5 mm – 50 mm (thicker available on request) | Custom sizes supported |
| Width | Up to 1500–2000 mm | Available |
| Length | Up to 6000–12000 mm or cut-to-length | Available |
| Surface Finish | 2B, No.1, BA, No.4 | Available |
| Certification | EN 10204 3.1 / Mill Test Certificate | Available |
SHH STEEL can supply dual-certified ASTM A240 / ASME SA240 Type 429 material when required by the project.
Chemical Composition
Typical Chemical Composition of AISI 429 (UNS S42900):
| Element | Content (%) |
|---|---|
| Carbon (C) | ≤ 0.12 |
| Silicon (Si) | ≤ 1.00 |
| Manganese (Mn) | ≤ 1.00 |
| Phosphorus (P) | ≤ 0.040 |
| Sulfur (S) | ≤ 0.030 |
| Chromium (Cr) | 14.00 – 16.00 |
| Nickel (Ni) | ≤ 0.75 |
| Iron (Fe) | Balance |
The defining feature of AISI 429 is the 14–16% chromium range. This places the grade between 12% Cr steels (410/410S) and 16–18% Cr steels (430). SHH STEEL carefully controls chromium and carbon so AISI 429 remains ferritic, formable and suitable for welded plate applications.
Mechanical Properties
Annealed Condition (typical ASTM A240 values)
| Property | Value |
|---|---|
| Tensile Strength | ≥ 450 MPa (65 ksi) |
| Yield Strength (0.2%) | ≥ 205 MPa (30 ksi) |
| Elongation (in 50 mm) | ≥ 22% |
| Hardness | ≤ 183 HBW / 89 HRBW |
AISI 429 is supplied annealed, with strength and ductility similar to Type 430. It is magnetic and does not harden by conventional quench and temper. SHH STEEL supplies AISI 429 meeting A240 mechanical limits.
Physical Properties
Density is approximately 7.70–7.75 g/cm³. Melting range is approximately 1480–1530°C.
Material Comparison
| Grade | UNS | Cr (%) | Stabilization / Mo | Corrosion Level | Typical Preference |
|---|---|---|---|---|---|
| AISI 410S | S41008 | 11.5–13.5 | Low carbon | Lower | Welded 12% Cr constructions |
| AISI 409 | S40900 | 10.5–11.75 | Titanium | Lower | Automotive exhaust |
| AISI 429 | S42900 | 14.0–16.0 | — | Medium | Intermediate ferritic plate |
| AISI 430 | S43000 | 16.0–18.0 | — | Better | General ferritic / decorative |
| AISI 434 | S43400 | 16.0–18.0 | Molybdenum | Better pitting | Automotive trim / chloride atmospheres |
| AISI 439 | S43035 | 17.0–19.0 | Titanium | Better welded | Stabilized higher-Cr ferritic |
AISI 429 is selected when corrosion resistance must be better than A240 410 or A240 409, but full 430 chemistry is not required. For decorative or higher atmospheric resistance, SHH STEEL recommends A240 430. For welded high-temperature ferritic service, compare with A240 439.
Corrosion Resistance
AISI 429 offers moderate corrosion resistance, better than 410/409 because of the higher chromium content. It performs well in mild atmospheres, fresh water, many food-contact and industrial environments, and some nitric-acid related conditions.
It is not equivalent to austenitic grades such as a240 304 or a240 316l in chloride service. For better pitting resistance in the 400 series, SHH STEEL recommends A240 434 or A240 444.
Weldability
AISI 429 can be welded by standard fusion methods. Matching 429/430-type filler metals are commonly used. As with other ferritic grades, heat input should be controlled to limit grain growth in the heat-affected zone.
Preheat and post-weld heat treatment depend on thickness and restraint. SHH STEEL recommends proper welding procedures and post-weld cleaning. For more demanding welded ferritic service, A240 439 is often preferred because of titanium stabilization.
Heat Treatment
AISI 429 is normally supplied in the annealed condition by SHH STEEL.
Annealing restores ductility after hot working or cold forming and optimizes corrosion resistance. The grade cannot be hardened by conventional quench and temper. SHH STEEL controls heat treatment so AISI 429 remains formable and weldable.
Surface Finishes
| Finish | Description | Typical Use / Keywords |
|---|---|---|
| 2B | Cold-rolled, annealed, pickled, skin-passed | AISI 429 2B – most common for sheet and thin plate |
| No.1 | Hot-rolled, annealed and pickled | AISI 429 No.1 / A240 429 No.1 – industrial plate |
| BA | Bright Annealed | AISI 429 BA – cleaner surface applications |
| No.4 | Brushed finish | AISI 429 No.4 – architectural surfaces |
SHH STEEL regularly supplies AISI 429 in 2B and No.1 finishes, and can provide other finishes according to project requirements.
Tolerances
Dimensional tolerances for AISI 429 Stainless Steel Plate supplied by SHH STEEL generally conform to ASTM A480 practices.
Typical available size range is thickness 0.5 mm – 50 mm, width up to 1500–2000 mm, and length up to 6000–12000 mm or cut-to-length. SHH STEEL provides precise dimensional control and can support tighter tolerances when required.
Equivalent Material Grades
| Grade / Designation | Standard / Region | Notes |
|---|---|---|
| AISI 429 | AISI | Main commercial keyword |
| A240 Type 429 | ASTM A240 / ASME SA240 | Plate specification |
| UNS S42900 | Unified Numbering System | Primary UNS designation |
| SUS429 | JIS (Japan) | Japanese equivalent |
| Related 14–16% Cr ferritic | EN / GB | Closest national grades |
| Related 410S / 430 / 439 | Multiple | Nearby 400-series options |
Related grades for comparison include A240 410, A240 410S, A240 430, A240 409, A240 439 and A240 434.
Applications
AISI 429 is selected for ferritic fabrications that need more corrosion resistance than 410/409 without moving fully to 430. Typical applications of AISI 429 include:
| Industry / Sector | Typical Components / Equipment (with keywords) |
|---|---|
| Chemical & Process | AISI 429 tanks, covers and welded process parts |
| Automotive | AISI 429 stamped and fabricated components |
| Food & Household Equipment | AISI 429 parts in mild corrosive service |
| General Fabrication | AISI 429 frames, panels and structural plate parts |
| Architecture & Interior | AISI 429 2B / No.4 panels and decorative fabrications |
| Industrial Equipment | A240 Type 429 No.1 plate for welded ferritic constructions |
SHH STEEL supplies AISI 429 for these applications with consistent quality. For related industry solutions, see our equipment manufacturing, construction industry and machinery industry pages. Supporting services include steel cutting services and steel welding services.
Why Choose SHH STEEL
SHH STEEL is a China steel mill-Direct Supply specializing in stainless steel plate and sheet. By working directly with major Chinese stainless steel mills, SHH STEEL supplies AISI 429 with the following advantages:
- Genuine China steel mill-Direct Supply pricing
- Consistent quality and complete heat traceability
- Full Mill Test Certificates (EN 10204 3.1)
- 14–16% Cr AISI 429 material positioned between 410 and 430
- Flexible dimensions and surface finishes (including AISI 429 2B and AISI 429 No.1)
- Technical support for selection among AISI 410S, 429, 430, 434 and 439
- Value-added services including steel cutting services, steel welding services and worldwide shipping service
For more information about our company and full product range, please visit China steel Mill Agent-SHH STEEL.
FAQ
- What are the other common names for AISI 429?AISI 429 is also known as ASTM A240 Type 429, UNS S42900, SUS429 and 429 stainless steel plate. SHH STEEL can certify the required designation.
- What is the difference between AISI 429 and AISI 430?AISI 429 has 14–16% chromium; AISI 430 has 16–18%. 430 generally offers better atmospheric corrosion resistance. SHH STEEL recommends 429 when an intermediate ferritic grade is specified.
- What is the difference between AISI 429 and AISI 410S?410S is a low-carbon 12% Cr grade for welded constructions. AISI 429 has higher chromium and better corrosion resistance. SHH STEEL can supply both according to the drawing.
- Is AISI 429 magnetic?Yes. AISI 429 is ferritic and remains magnetic in the annealed condition.
- What is the density of AISI 429?Approximately 7.70–7.75 g/cm³. SHH STEEL provides mill certificates confirming chemistry and mechanical properties.
- Can AISI 429 replace 304?Only in mild environments. 304 offers much better corrosion resistance, especially in chlorides. SHH STEEL recommends 304 or 316L when austenitic performance is required.
- Does SHH STEEL supply dual-certified ASTM A240 Type 429 / AISI 429 material?Yes, SHH STEEL commonly supplies dual-certified material upon request.
Conclusion
AISI 429 Stainless Steel Plate is a 14–16% chromium ferritic grade that sits between 410/410S and 430. It is a practical choice when better corrosion resistance than 12% Cr steels is needed, without moving to full 430 chemistry.
As a professional China steel mill-Direct Supply, SHH STEEL provides high-quality AISI 429 Stainless Steel Plate with competitive pricing, full certification and complete technical support.
Contact SHH STEEL today for stock availability, surface finish options (including AISI 429 2B and AISI 429 No.1), or a competitive quotation.
AISI 429 Stainless Steel Plate, AISI 429, A240 Type 429, UNS S42900, 429 China steel mill-Direct Supply, SUS429, AISI 429 supplier
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