Duplex Steel Alloy 329 Fasteners Overview
Duplex Steel Alloy 329 Fasteners secure bolted connections in piping and equipment exposed to chlorides and acidic process streams, where austenitic bolting corrodes faster. As one of the original duplex grades, its higher chromium content gives strong general and pitting corrosion resistance, historically used in pulp & paper, chemical processing and marine bolted joints.
Quick Specifications of Duplex Steel Alloy 329 Fasteners
Duplex Steel Alloy 329 Fasteners are produced to internationally recognized bolting specifications; confirm exact figures against the mill test certificate for your order.
| Field | Detail |
|---|---|
| Material/Grade | Duplex Steel Alloy 329 |
| UNS | S32900 |
| Werkstoff Number | *Confirm on request* |
| Standards | ASTM A276, ASTM A479 |
| Form | Bolts, Nuts, Studs |
| Finish | Passivated |
| Heat Treatment | Solution Annealed |
| Certification | EN 10204 3.1 |
Equivalent Grades of Alloy 329
Alloy 329 is recognized under UNS S32900; equivalent EN and trade designations should be confirmed against the applicable standard before publishing.
| UNS | Werkstoff Number | EN Steel Name | Common Trade Name | ASTM/ASME Standard |
|---|---|---|---|---|
| S32900 | *Confirm on request* | *Confirm on request* | Type 329 | ASTM A276/A479 |
Chemical Composition of Alloy 329
Alloy 329 is a higher-chromium, lower-molybdenum duplex grade relative to 2205. Exact composition limits vary by specification and should be confirmed against ASTM A276/A479 before publishing rather than stated here as fixed figures.
| Element | Composition (%) |
|---|---|
| Chromium (Cr) | *Confirm exact range against ASTM A276* |
| Nickel (Ni) | *Confirm exact range against ASTM A276* |
| Molybdenum (Mo) | *Confirm exact range against ASTM A276* |
| Iron (Fe) | Balance |
Physical Properties of Duplex Steel Alloy 329
Alloy 329's physical properties reflect its duplex structure; heat-specific figures should be confirmed against the mill test certificate.
| Property | Value |
|---|---|
| Density | *Confirm on request* |
| Melting Range | *Confirm on request* |
| Magnetic Behaviour | Magnetic (ferrite phase present) |
Mechanical Properties of Duplex Steel Alloy 329 Fasteners
Mechanical properties for Alloy 329 Fasteners should be confirmed against ASTM A276/A479 for the specific size and condition ordered rather than stated here as fixed minimums.
| Property | Minimum Value |
|---|---|
| Tensile Strength | *Confirm against ASTM A276/A479* |
| Yield Strength | *Confirm against ASTM A276/A479* |
| Elongation | *Confirm against ASTM A276/A479* |
| Condition | Solution Annealed |
Corrosion Resistance of Duplex Steel Alloy 329
- Duplex Steel Alloy 329 Fasteners carry a comparatively high chromium content among duplex grades, giving strong resistance to localized attack.
- Pitting resistance: high resistance to chloride-induced pitting in acidic and brine service.
- Crevice resistance: performs reliably under bolt heads, nuts and flange faces where crevice corrosion typically starts.
- Chloride SCC resistance: resists stress corrosion cracking that limits austenitic bolting in hot chloride environments.
- ⚠️ Flag: exact PREN value not stated here – confirm against verified composition before publishing.
Heat Resistance of Duplex Steel Alloy 329
Alloy 329 fasteners are generally suited to continuous service across a moderate temperature range typical of early duplex grades; industry guidance commonly limits continuous use to roughly 300°C to avoid embrittlement risk. Always confirm exact service limits against the governing standard and application before specifying.
Key Properties of Duplex Steel Alloy 329 Fasteners
Beyond corrosion and heat performance, Alloy 329 fasteners offer these additional properties.
- Higher strength than standard austenitic stainless bolting
- Good resistance to sulfuric and other acidic media
- Machinable with standard tooling at moderate cutting speeds
- Long field history in pulp & paper and chemical processing
Benefits of Duplex Steel Alloy 329 Fasteners
Choosing Alloy 329 fasteners from Zeon Exports delivers measurable advantages for your project.
- Lower long-term maintenance from superior corrosion resistance
- Full MTC 3.1 documentation for project QA/QC requirements
- Multiple sizes, threads and finishes to match exact project specs
- Reliable bulk supply with consistent ready stock
- Competitive export pricing for large industrial orders
- Fast dispatch to global project sites and ports
Related Products
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Request a Quote for Duplex Steel Alloy 329 Fasteners
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Frequently Asked Questions About Duplex Steel Alloy 329 Fasteners
Common questions about Duplex Steel Alloy 329 Fasteners, answered below.
Q1: What is Duplex Steel Alloy 329?
Ans. Alloy 329 (UNS S32900) is one of the earliest duplex stainless steels, with a higher chromium content than 2205 for strong acid and chloride resistance.
Q2: Which fastener types are available in Alloy 329?
Ans. We supply bolts, nuts and studs to ASTM A276/A479 across standard thread sizes and lengths.
Q3: What standards do Alloy 329 fasteners meet?
Ans. Fasteners are manufactured to ASTM A276/A479, certified to EN 10204 3.1 mill test certificates.
Q4: How does Alloy 329 compare to Alloy 2205?
Ans. Alloy 329 carries more chromium and less molybdenum than 2205, giving strong acid resistance; confirm exact PREN for your specific application.
Q5: Is Alloy 329 magnetic?
Ans. Yes, like other duplex grades, Alloy 329 is magnetic due to its ferrite phase content.
Q6: Can Alloy 329 fasteners be used in chemical processing?
Ans. Yes, Alloy 329 has a long history of use in pulp & paper and chemical processing bolted joints for its acid resistance.
Q7: What certification is provided with orders?
Ans. Every order ships with EN 10204 3.1 mill test certificates confirming grade, heat and dimensions.
Q8: Does Zeon Exports supply custom sizes?
Ans. Yes, fasteners are available in custom thread sizes and lengths on request for bulk industrial orders.
