430 steel (S43000): properties, composition, equivalents
430 stainless steel (UNS S43000, EN 1.4016): 16–18 % Cr ferritic, no nickel, magnetic. 205 MPa (30 ksi) yield, 450 MPa (65 ksi) tensile. Composition, properties, 430 vs 304, and 1.4016/SUS430 equivalents.
What is 430?
Type 430 is the workhorse ferritic stainless steel: 16–18 % chromium, no nickel, body-centred cubic structure, therefore magnetic and — because it carries no nickel — 30–40 % cheaper than 304. UNS S43000, EN 1.4016. It offers good resistance to mild atmospheres, fresh water, food acids and nitric acid, a bright polished or brushed surface, and easier machining than the austenitics; in return it gives up formability, weld toughness, low-temperature toughness and chloride resistance.
The classic uses follow from that trade-off: appliance panels, dishwasher tubs, range hoods, sink surrounds, automotive trim, decorative tube and interior architecture — parts that are stamped or lightly drawn, seldom welded and never exposed to salt. Where welding is needed, the stabilized cousins 439 and 441 (EN 1.4510, 1.4509) avoid grain-boundary sensitization and grain growth in the HAZ.
Minimum properties are 205 MPa yield and 450 MPa tensile; typical 2B sheet is stronger (≈ 320/500 MPa) and has a lower work-hardening rate than 304, so press loads and spring-back are smaller. EN 1.4016, JIS SUS430, GB 10Cr17 and GOST 12Kh17 are the same grade.
430 chemical composition
| Element | Mass % | Note |
|---|---|---|
| C | ≤ 0.12 | |
| Mn | ≤ 1 | |
| P | ≤ 0.04 | |
| S | ≤ 0.03 | |
| Si | ≤ 1 | |
| Cr | 16 – 18 | |
| Ni | ≤ 0.75 | residual only |
ASTM A240/A240M-22 Table 1 (S43000). EN 1.4016 (X6Cr17): C ≤ 0.08, Cr 16–18 — tighter on carbon. Typical mill analysis C 0.04–0.06, Cr 16.2–16.8.
430 mechanical properties
| Thickness / condition | Yield strength ReH / Rp0.2 MPa (ksi) | Tensile strength Rm MPa (ksi) | Elongation A % | Hardness |
|---|---|---|---|---|
| Sheet, strip, plate — annealed (A240) | ≥ 205 (≥ 29.7) | ≥ 450 (≥ 65.3) | 22 | ≤ 183 HB / ≤ 89 HRB |
| Bar — annealed (A276) | ≥ 205 (≥ 29.7) | ≥ 450 (≥ 65.3) | 20 | — |
| Bar — cold finished ≤ 12.7 mm | ≥ 380 (≥ 55.1) | ≥ 585 (≥ 84.8) | 12 | — |
| EN 1.4016 cold-rolled sheet, +A (for comparison) | ≥ 260 (≥ 37.7) | 450–600 (65.3–87.0) | 20 | ≤ 200 HB |
ASTM A240 Table 2; typical annealed 2B sheet: yield 300–340 MPa, tensile 480–520 MPa, elongation 25–30 %. r-value ≈ 1.0–1.4 (good drawability for a ferritic).
Impact toughness
430 requires a minimum Charpy V-notch energy of 20 J at 0 °C (typical, thin sheet; transition around 0 to +20 °C for > 3 mm). Ferritic steels have a ductile-to-brittle transition; 430 is not a low-temperature material and thick sections are notch-sensitive after welding.
430 equivalent grades
| Grade | System | Match | Why / differences |
|---|---|---|---|
| 430S17 | BS (superseded British) | Identical | BS 1449 430S17: C ≤ 0.08, Cr 16–18. |
| 1.4016 | EN (European) | Identical | X6Cr17: C ≤ 0.08, Cr 16–18. Dual-certified 430/1.4016 sheet is standard in Europe. |
| 10Cr17 | GB/T (China) | Identical | GB/T 20878 10Cr17 (formerly 1Cr17). |
| 12Kh17 | GOST (Russia/CIS) | Identical | GOST 5632 12Kh17: C ≤ 0.12, Cr 16–18. |
| SUS430 | JIS (Japan) | Identical | JIS G4305 SUS430: C ≤ 0.12, Cr 16–18. |
| 439 / 1.4510 | AISI / SAE | Near | Ti-stabilized 17 % Cr (S43035 / X3CrTi17): weldable without sensitization, same corrosion class — the upgrade for welded parts. |
| 441 / 1.4509 | AISI / SAE | Near | Nb+Ti dual-stabilized 18 % Cr for exhaust systems and heat exchangers. |
| 409 / 1.4512 | AISI / SAE | Functional | 11 % Cr ferritic for exhausts; cheaper, lower corrosion resistance. |
| 304 | AISI / SAE | Functional | Austenitic 18-8: better corrosion resistance, formability and weldability; 430 replaces it on cost in dry indoor service. |
| 410 | AISI / SAE | Functional | Ferritic 17 % Cr: better corrosion resistance, not hardenable. |
Identical = same composition and mechanical limits within rounding. Near = one limit differs (e.g. carbon max or impact temperature). Functional = interchangeable for most uses after an engineering check. Full cross-reference for 430 →
Old and superseded designations
| Old name | Standard | Note |
|---|---|---|
| 1.4016 / X6Cr17 | EN 10088 | European twin (older DIN name X8Cr17). |
| S43000 | UNS | 430F (S43020) = free-machining; 430Ti / 439 (S43035) = Ti-stabilized weldable version. |
| 430S17 / 430S15 | BS 1449 / BS 970 | |
| CB-30 | ACI / ASTM A743 | Cast equivalent. |
Product forms and tolerance standards
Product forms: sheet, strip and plate (ASTM A240) — mostly cold-rolled sheet ≤ 3 mm, bar and wire (A276, A493), welded tube (A268 TP430), castings as CB-30.
Dimensional tolerances: sheet/plate: ASTM A480 (finishes 2B, BA, No. 4); bar: ASTM A484.
Key property values
430 stainless steel yield strength
Minimum 205 MPa (30 ksi) annealed; typical 300–340 MPa; cold-finished bar ≥ 380 MPa.
430 tensile strength
Minimum 450 MPa (65 ksi); typical 480–520 MPa annealed.
430 hardness
Annealed max 183 HB / 89 HRB (≈ 190 HV); typical 150–170 HB. Slight hardening possible by quenching (martensite from the 0.12 % C), but 430 is not a hardenable grade — use 410/420 for that.
Corrosion resistance
PREN ≈ 16–18. Resists indoor and rural atmospheres, fresh water, dilute nitric acid, food acids, alkalis; stains in urban/industrial air, pits in chlorides, poor in reducing acids. Roughly equivalent to 304 in mild environments but markedly worse in chloride-containing ones.
Heat resistance
Oxidation resistance to 815 °C (1500 °F) continuous, 870 °C intermittent — better than 304 for cyclic heating because its expansion coefficient is lower. 475 °C embrittlement on long exposure at 400–540 °C; sigma phase at 550–800 °C.
Physical properties
Density 7.7 g/cm³, E = 200 GPa, expansion 10.4 × 10⁻⁶/K (0–100 °C — close to carbon steel), conductivity 26 W/m·K (higher than austenitics), resistivity 0.60 µΩ·m, ferromagnetic.
Heat treatment
Anneal 760–815 °C (1400–1500 °F), air cool or slow cool; do not exceed 900 °C (grain growth and partial austenite → martensite on cooling). Stress relieve 200–300 °C.
Weldability
Weldable with care: the HAZ coarsens and may sensitize, lowering toughness and corrosion resistance. Use ER308L/E309L filler for ductility, or matching ER430 when colour match matters; keep heat input low, preheat 150–200 °C for > 3 mm, post-weld anneal 760–815 °C for critical parts. For routinely welded products specify 439 or 441 instead.
Machining, forming and heat treatment
Machinability ≈ 55 % of B1112 — better than 304 (no work hardening); 430F (S43020, 0.15 % S min) is the free-machining version at ≈ 90 %. Forming: good for bending, roll forming and moderate drawing; ridging/roping may appear on deep-drawn surfaces (use ridging-resistant 430 grades). Polishes to a high lustre; standard finishes 2B, BA, No. 4.
Typical applications
- Appliance panels: refrigerator doors, dishwasher tubs, range hoods, microwave cavities
- Kitchen equipment and sink surrounds (dry or lightly wet)
- Automotive trim, mouldings, wheel covers
- Decorative tube, interior architectural cladding, lift panels
- Cutlery (blades as 420, handles as 430), hollowware
- Heat-exchanger and furnace parts to 800 °C (non-welded)
- Coins and tokens (with Ni or Cu variants)
430 compared with related grades
Frequently asked questions
What is the difference between 430 and 304 stainless steel?
430 is ferritic (16–18 % Cr, no Ni): magnetic, cheaper, less formable, lower corrosion resistance and poorer weldability. 304 is austenitic (18 % Cr, 8 % Ni): non-magnetic, more corrosion-resistant, deep-drawable and readily welded. Use 430 for dry, decorative, stamped parts; 304 for wet, welded or outdoor ones.
Is 430 stainless steel magnetic?
Yes — it is ferritic, like carbon steel. This is the quickest way to tell 430 from 304 in the field.
Does 430 stainless rust?
It stays bright in dry indoor and rural environments but stains and pits with salt, road de-icers, urban pollution and chloride cleaners. It is not suitable for marine or pool use.
Can 430 be hardened?
Not usefully. Its low carbon (≤ 0.12 %) produces only a little martensite on quenching. Hardenable stainless steels are the martensitic grades 410, 420 and 440.
What is 430 equivalent to in EN?
EN 1.4016 (X6Cr17). The EN grade caps carbon at 0.08 % versus 0.12 % for ASTM 430; European mills dual-certify.
Is 430 food-safe?
Yes for dry and mildly wet food contact (bakeware, appliance interiors, cutlery handles). For process equipment with acidic or salty foods, 304 or 316 are specified.
Related grades
Verified against ASTM A240/A240M-22; ASTM A240/A240M-22 Tables 1–2; ASTM A276/A276M-23; EN 10088-2:2014 (1.4016 comparison). Last checked: September 2026.