439
Data verified439 is a stabilised 17–19% chromium ferritic stainless with low carbon and nitrogen, giving better formability, weldability and corrosion resistance than 430. It is used for exhaust systems and heat-exchanger tubing as a lower-cost alternative to 304.
Chemical composition
| Element | Content (%) |
|---|---|
| C | ≤0.03 |
| Si | ≤1.00 |
| Mn | ≤1.00 |
| P | ≤0.040 |
| S | ≤0.030 |
| Cr | 17.00–19.00 |
| Ni | ≤0.50 |
| Ti | 0.20+4×(C+N)–1.10 |
| N | ≤0.03 |
Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.
Properties
| Delivery condition | Annealed |
| Hardness | ≤183 HB (annealed) |
| Tensile strength | 415–585 MPa |
| Density | 7.70 g/cm³ |
| Magnetic | Yes |
Heat treatment
Anneal 845–900 °C, air cool. Titanium stabilisation with low interstitials keeps the structure fully ferritic.
Equivalent grades
| Standard | Designation |
|---|---|
| din | 1.4510 |
| aisi | 439 |
| gb | 06Cr17Ti |
Compare side by side: 439 vs 430 · 439 vs 444
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: Automotive exhaust manifolds and converters, heat-exchanger tubes, sugar industry equipment, appliance parts.
Processing: Good deep drawing for a ferritic; welds satisfactorily in thin sections; resists chloride stress-corrosion cracking that affects austenitics.
FAQ
- 439 vs 304 tube?
- 439 costs less (no nickel), resists chloride stress corrosion, but has lower general corrosion resistance and toughness; it is common in exhaust and sugar-evaporator tubing where those trade-offs suit.
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Ask for a quotationVisit NasteelSource: ASTM A240 / EN 10088 published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.
