ASTM A249 TP201 / TP201LN Stainless Steel Welded Tubes

What is ASTM A249?

ASTM A249 is the standard specification for welded austenitic stainless steel tubing intended for boilers, superheaters, heat exchangers, and condensers. Tubes produced under this specification must meet strict requirements for:

Automatic welding without filler metal

Cold working of the weld and/or base metal before final heat treatment

Solution annealing at a minimum of 1900℉ (1040℃)

Comprehensive mechanical and nondestructive testing

This ensures excellent corrosion resistance, dimensional stability, and long service life in high-pressure and high-temperature applications.

Manufacturing Process  Of ASTM A249 TP201 / TP201LN Stainless Steel Welded Tubes

Welding
Tubes are manufactured using an automatic fusion welding process without the addition of filler metal, ensuring consistent weld quality.

Cold Working
After welding and prior to final annealing, the tubes must be cold worked to enhance the mechanical properties and refine the weld area. The cold work may apply to the weld seam, or to both weld and base metal, depending on purchaser requirements.

Heavily Cold Worked (HCW) Option
For HCW tubes, a minimum 35% reduction in wall thickness and weld area is required. Before cold working, 100% radiographic inspection of the weld is performed per ASME BPVC Section VIII, Division 1, Paragraph UW-51.

Final Heat Treatment
All tubes are solution annealed at temperatures ≥1900℉ (1040℃) to restore corrosion resistance and mechanical properties.

Material Grades: TP201 vs TP201LN

TP201 – Cost-Effective Austenitic Stainless Steel

TP201 is a manganese- and nitrogen-strengthened austenitic stainless steel designed as an economical alternative to 300 series alloys. It offers:

Good strength and formability

Moderate corrosion resistance

Lower nickel content for cost efficiency

Suitable for non-critical pressure systems and decorative applications

TP201LN – Enhanced Version with Superior Corrosion Resistance

TP201LN is a low-carbon, nitrogen-enriched, and copper-alloyed variant of TP201. It delivers:

Improved weldability and resistance to intergranular corrosion

Higher yield strength and elongation

Better performance in mildly corrosive environments

Suitable for industrial heat exchangers, condensers, and pressure tubing

Comparison Table – TP201 vs TP201LN

Property	TP201	TP201LN
Carbon (C)	≤0.15%	≤0.03%
Manganese (Mn)	5.5–7.5%	6.4–7.5%
Chromium (Cr)	16.0–18.0%	16.0–17.5%
Nickel (Ni)	3.5–5.5%	4.0–5.0%
Nitrogen (N)	≤0.25%	0.10–0.25%
Copper (Cu)	—	≤1.0%
Yield Strength (min)	260 MPa	310 MPa
Elongation (min)	35%	45%
Rockwell Hardness (max)	B95	B100
Vickers Hardness (max)	230	263

Dimensions

According to ASTM A249 specification, Ganyeah Group supplies welded stainless steel tubes in the following size range:

Inside Diameter (ID): From 1/8 inch (3.2 mm)

Outside Diameter (OD): Up to 12 inches (304.8 mm)

Wall Thickness (WT): From 0.015 inch (0.4 mm) to 0.320 inch (8.1 mm)

Custom dimensions may be supplied if all other specification requirements are met.

Mechanical Properties

Property	TP201	TP201LN
Tensile Strength (min)	655 MPa	655 MPa
Yield Strength (min)	260 MPa	310 MPa
Elongation (in 2 in. / 50 mm)	≥35%	≥45%
Rockwell Hardness (HRB max)	B95	B100
Vickers Hardness (HV max)	230	263

All tubes are solution heat treated at ≥1900℉ (1040℃).

Quality Control & Testing

To meet ASTM A249 standards, each tube is subject to:

Eddy Current or Air-under-Water Testing

Flattening Test / Flange Test / Reverse Bend Test

Hardness Inspection

PMI (Positive Material Identification)

Dimensional and Visual Inspections

3.1/3.2 Material Test Certificates

Why Choose Ganyeah Group?

20+ Years of Stainless Steel Pipe Manufacturing

Exported to 60+ Countries Worldwide

ISO 9001, CE, SGS Certified

Strict QC and Full Material Traceability

OEM and Custom Project Support

Request a Quote

Looking for reliable ASTM A249 TP201 or TP201LN stainless steel tubes for your project?

Contact Ganyeah Group for pricing, technical consultation, or free samples.