Key Feature

The Enhanced Titanium-Stabilized Ferritic Stainless Steel Pipe. Improved corrosion resistance over 430 with titanium stabilization for better weldability and intergranular corrosion resistance in piping applications.

An upgraded 430-grade pipe with better overall performance while maintaining cost-effectiveness.

Common Designations

UNS S43035
AISI 439
ASTM A268 TP439 (Seamless Ferritic Pipe)
EN 1.4510, X3CrTi17
JIS SUS439LX
GM 439M

Often specified in automotive and appliance industry standards for piping.

Chemical Composition (Typical wt.%)

C: ≤ 0.07
Cr: 16.0 - 19.0
Ti: 0.50 - 1.00Mn: ≤ 1.00
Si: ≤ 1.00
Ni: ≤ 0.50
P: ≤ 0.040
S: ≤ 0.030

Titanium content (typically 0.5-1.0%) provides stabilization and improved properties for piping.

Mechanical Properties

Tensile Strength: ≥ 415 MPa
Yield Strength: ≥ 240 MPa
Elongation: ≥ 20%
Hardness: ≤ 183 HB

Similar mechanical properties to 430 but with better corrosion resistance for piping applications.

Physical Properties

Density: 7.70 g/cm³
Melting Range: 1425 - 1510 °C
Thermal Expansion: 10.8 × 10⁻⁶/K (20-400°C)
Thermal Conductivity: 25.0 W/m·K (100°C)
Strongly magnetic

Low thermal expansion similar to carbon steel; beneficial for thermal cycling in piping systems.

Corrosion Resistance

Good resistance to atmospheric corrosion, nitric acid, organic acids, and fresh water. Better than 430, approaching 304 in many environments.

Suitable for automotive exhaust, appliance, and architectural piping applications.

Welding Characteristics

Excellent weldability due to titanium stabilization
No post-weld heat treatment requiredMaintains corrosion resistance in weld zoneMatching filler metals recommended

Titanium prevents sensitization and maintains properties across pipe welds.

Pressure Ratings

Schedule 10/40: Standard piping applications
ASME B31.3 compliant for specific services
Similar to 430 in pressure capability

Suitable for low to moderate pressure applications in appropriate environments.

Temperature Limits

Continuous Service: Up to 800°C
Maximum Service: 850°C
Avoid: 475-900°C (embrittlement range)
Minimum Service: -30°C

Good high-temperature stability for many industrial piping applications.

Key Standards

ASTM A268 TP439: Seamless Ferritic Pipe
ASTM A791: Welded Ferritic Pipe
EN 10216-5: Seamless Pressure Tubes
JIS G3463: Stainless Steel Pipe
SAE J1396: Automotive Standards

Widely used in automotive exhaust and appliance piping applications.

Common Applications

• Automotive Exhaust Piping: Muffler pipes, catalytic converter housings, exhaust pipes, tailpipes
• Appliance Piping: Dishwasher drain pipes, washing machine tubs, oven exhaust ducts
• Heat Exchanger Piping: Automotive radiator tubes, charge air cooler piping
• Architectural Piping: Handrails, guardrails, decorative pipe structures (indoor)
• Food Service Piping: Sink drains, kitchen exhaust ducts, mild service food piping
• Industrial Piping: Ventilation ducting, fume exhaust stacks, mild chemical piping
• Furniture Piping: Outdoor furniture frames, display system structures

Specifically designed for cost-effective piping applications requiring better performance than 430.