AMS 5571 347 aerospace-grade Stainless Steel tubing

If you are seeking stainless steel tubing capable of continuous service between 800°F and 1650°F (427–900°C)-without the need for post-weld solution annealing and with excellent resistance to intergranular corrosion-AISI 347 seamless tubing is the premier stabilized austenitic stainless steel choice for applications such as aircraft engine exhaust systems, high-temperature chemical piping, and heat exchangers. Through dual stabilization with Niobium (Nb) and Tantalum (Ta), it completely eliminates the risk of grain-boundary carbide precipitation within the chromium-carbide precipitation range (800–1500°F) while offering superior high-temperature creep strength and stress-rupture properties compared to Grade 321.

 

What is AMS 5571?

AMS 5571 is an aerospace material specification issued by SAE International covering seamless, corrosion- and heat-resistant Type 347 stainless steel tubing (UNS S34700) in the solution heat-treated condition.

 

What is 347 aerospace-grade seamless stainless steel tubing?

AISI 347 aerospace-grade seamless stainless steel tubing (UNS S34700) is a niobium-tantalum stabilized austenitic stainless steel product manufactured via piercing and cold-drawing or cold-rolling processes, ensuring the absence of weld-related weak points. Its composition-featuring 17–19% Cr, 9–13% Ni, and Nb ≥ 10×C%-enables it to maintain structural integrity and resistance to intergranular corrosion within the high-temperature range of 800–1650°F. It is widely used in applications such as aero-engine exhaust manifolds, turbine hot-gas ducts, chemical superheaters, and nuclear-grade heat exchangers.

 

AMS 5571 TP347 Stainless Steel Tube Specification

Item	Example Specification
Material Grade	AISI 347 / UNS S34700 (or 347H / S34709)
Applicable Standard	AMS 5571
Outside Diameter (OD)	1/2" (12.7 mm) ± 0.05 mm
Wall Thickness	0.065" (1.65 mm) ± 5%
Length	6 m (20 ft) / Custom
Delivery Condition	Annealed (Solution Annealed)
Surface Finish	2B / Bright Annealed / Inner Polished
End Type	Plain End + Protective Caps
Quantity	500 kg
Inspection Requirements	EN 10204 3.2 + PMI + Eddy Current Testing (ET)
Certificates	MTC + Individual Tube ET Reports + PMI Reports
Packaging	Wooden Cases + Moisture-Proof Film + Plastic End Caps + Labels
Trade Terms	FOB Shanghai / CIF Long Beach
Lead Time	25–35 Days
Special Requirements	NADCAP Certification / AS9100 / Aerospace Material Approval

 

Chemical Composition Comparison: TP347 vs TP347H

Cr (Chromium)	17.0–19.0%	17.0–19.0%	17.0–19.0%	18.0–20.0%
Ni (Nickel)	9.0–13.0%	9.0–13.0%	9.0–12.0%	8.0–11.0%
Mn (Manganese)	≤ 2.00%	≤ 2.00%	≤ 2.00%	≤ 2.00%
Si (Silicon)	≤ 1.00%	≤ 1.00%	≤ 1.00%	≤ 1.00%
P (Phosphorus)	≤ 0.045%	≤ 0.045%	≤ 0.045%	≤ 0.045%
S (Sulfur)	≤ 0.030%	≤ 0.030%	≤ 0.030%	≤ 0.030%
Nb (Niobium / Cb)	≥ 10×C% and ≥ 1.00%	≥ 8×C% and ≥ 1.00%	-	-
Ti (Titanium)	-	-	≥ 5×C% and ≥ 0.70%	-
Mo (Molybdenum)	-	-	-	-

 

Aerospace-Grade Mechanical Properties By Tube Diameter (AMS 5571)

Nominal Outside Diameter (OD)	Nominal Wall Thickness	Tensile Strength UTS (ksi)	Yield Strength YS (ksi)	Elongation
≤ 0.188"	≤ 0.016"	75–120 max	-	35%
≤ 0.188"	> 0.016"	75–105 max	30 min	35%
> 0.188"–0.500"	≤ 0.010"	75–115 max	30 min	35%
> 0.188"–0.500"	> 0.010"	75–105 max	-	35%
> 0.500"	All wall thicknesses	75–100 max	30 min	35%

 

To provide you with a more accurate quote, could you please provide the following information?
Required outer diameter (OD) and wall thickness?
Estimated order quantity (in kilograms or feet)?
Are there any specific aerospace specifications or testing requirements (e.g., AMS standards)?

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What Is the Typical MOQ and Lead Time for 347 Stainless Steel Tubes?

Item	Typical Range
MOQ (Industrial Grade)	500 kg–1 ton
MOQ (Aerospace Grade, AMS 5571)	100–500 kg
Lead Time (Standard Sizes, In Stock)	7–15 days
Lead Time (Custom Sizes)	25–45 days
Lead Time (Aerospace Grade + Individual Tube Testing)	30–60 days

Recommendation: Place orders for aerospace projects 3–4 months in advance, as production capacity for AMS 5571 tubing is limited and individual eddy-current testing is time-consuming.

 

We offer free samples (1–2 pieces, ≤ 1 m) with freight collect.
Aerospace-grade samples must be taken from certified heats; stock remnants are not permitted.
Quality Control:
PMI (verification of Nb content)
Tensile testing (UTS/YS/El)
Eddy current testing (internal defects)
Metallographic examination (fully austenitic, no delta ferrite)
Dimensional inspection (OD, wall thickness, ovality)

Packaging for 347 Stainless Steel Pipe

Moisture protection: Desiccant and moisture-proof film inside wooden crates (especially for sea shipments exceeding 30 days)
Deformation prevention: Plastic protective caps on pipe ends to prevent impact damage
Marking: Each pipe/bundle marked with: Material (347 / 347H); Standard (AMS 5571); Batch No. / Heat No.; OD × Wall × Length; Quantity / Weight

 

FAQ

What is Difference Between 347 and 347H Stainless Steel?

The core difference between 347 and 347H stainless steel is their carbon content. The letter "H" stands for "High Carbon," and the higher carbon level in 347H provides improved high-temperature strength and creep resistance, making it more suitable for prolonged exposure to elevated temperatures.

Key Parameter Comparison

Property / Parameter	347 (UNS S34700)	347H (UNS S34709)
Carbon Content	Maximum 0.08% (≤0.08%)	0.04–0.10%
High-Temperature Strength & Creep Resistance	Suitable for general high-temperature service	Higher, particularly above 538°C (1000°F)

 

What is the operating temperature range for 347 stainless steel pipe?

Condition	Temperature Range
Continuous service (recommended)	-425°F to 1650°F (-250°C to 900°C)
Intermittent heating	Up to 1650°F (900°C)
ASME B31.1 recommendation (347H)	347H is preferred above 800°F (427°C)
Above 900°C (1650°F)	Not recommended; consider 310S / Inconel 600
Low-temperature service (< -425°F / -250°C)	Impact testing is required for verification

 

Can 347 replace 321?

It can be used as a substitute in some scenarios, but they are not freely interchangeable. The key difference is that 347 offers superior high-temperature creep and stress-rupture properties compared to 321; in aerospace projects, however, 347 and 321 are not interchangeable, and the specifications mandated by the OEM (specifically the AMS standards) must be strictly followed.