UNS S30403|1.4307|TP304L Seamless Stainless Steel Tube

Seamless Stainless Steel TP304L Tubes (UNS S30403) are premium low-carbon austenitic solutions engineered to eliminate carbide precipitation during welding, ensuring maximum structural integrity. As a specialized manufacturer based in Wenzhou, China, XinZhe produces high-performance 304L seamless tubing that strictly complies with ASTM A213, ASTM A269, and ASME SA213 international standards.

Due to its minimized carbon content, our TP304L tubing offers superior intergranular corrosion resistance, making it the ideal choice for heavy-gauge welded components in chemical processing, cryogenic applications, and pharmaceutical systems. Through advanced cold-drawing and bright annealing processes, XinZhe guarantees tight dimensional tolerances and a superior surface finish. Rely on our expertise for certified stainless steel solutions that deliver long-lasting durability in the most demanding corrosive environments.

Quantity:

Contact Now

What Is a Seamless Stainless Steel TP304L Tube?

Seamless TP304L (UNS S30403) tube is the low-carbon version of the standard 18-8 austenitic grade, engineered to prevent carbide precipitation in the heat-affected zone of welded joints. That single change delivers markedly better intergranular corrosion resistance after welding while keeping the excellent formability, toughness and general corrosion performance of the 304 family.

Seamless Stainless Steel TP304L Tube, also known as 1.4307 Stainless Steel Tube or UNS S30403 Tube, is a corrosion-resistant stainless steel tubing manufactured from a solid billet through a seamless process.

Unlike welded tubes, seamless TP304L tubing contains no weld seam, which significantly improves structural integrity, pressure resistance, and reliability in demanding industrial environments.

Because of its low carbon composition and excellent corrosion resistance, TP304L seamless stainless steel tube is widely used in industries such as oil & gas, chemical processing, pharmaceutical production, food processing, and aerospace engineering.

Common manufacturing standards include:

Key Features and Technical Advantages

The “L” in TP304L stands for Low Carbon, which provides important advantages during welding and fabrication.

TP304L contains maximum 0.03% carbon, compared to 0.08% in standard 304 stainless steel.

This significantly reduces the risk of chromium carbide precipitation, also known as sensitization, during welding.

Low Carbon Composition

TP304L contains maximum 0.03% carbon, compared to 0.08% in standard 304 stainless steel.

Improved Corrosion Resistance After Welding

Because carbide precipitation is minimized, TP304L stainless steel tubes maintain their corrosion resistance even in the heat-affected zone (HAZ).

Excellent Weldability

TP304L seamless tubes are ideal for systems requiring extensive welding, such as piping networks, instrumentation lines, and sanitary process systems.

Product Specifications and Data

Feature	Industrial Benefit
Seamless Construction	No weld seam means higher burst pressure and improved reliability
Resistance to Intergranular Corrosion	Ideal for welded components used in corrosive environments
High Dimensional Precision	Tight tolerances on outside diameter (OD) and wall thickness (WT)
Cryogenic Strength	Excellent toughness at extremely low temperatures
Smooth Internal Surface	Reduces fluid friction and prevents bacterial buildup

To provide a comprehensive overview of this high-performance material, here are the detailed technical specifications and performance data for 304L stainless steel.

Table 1: Chemical Composition

C	Si	Mn	P	S	Cr	Ni	Fe
≤ 0.035	≤ 1.00	≤ 2.0	≤ 0.045	≤ 0.03	18.0 - 20.0	8.0 - 12.0	Bal

Table 2: Mechanical Properties

Tensile Strength	Yield Strength	Elongation	Rockwell Hardness	Brinell Hardness
485-690 MPa	≥ 170 MPa	≥ 40%	≤ 90 HRB	≤ 192 HB

Property	TP304	TP304L
Carbon Content	Max 0.08%	Max 0.03%
Corrosion Resistance	Excellent	Superior after welding
Strength	Slightly higher	Slightly lower
Post-Weld Heat Treatment	Often required	Usually not required

Dimensional Standards and Tolerances

TP304L seamless tubes are supplied to the dimensional tolerances of ASTM A213 / A213M or ASTM A269, with outside diameter, wall thickness, ovality and straightness verified against ASTM A1016 / A1016M.

Table 3: The Standard of Stainless Steel Seamless Tube Size Tolerance Size Chart :

Standard	OD(D)	Tolerance（MM)		Thickness(S)	Tolerance(MM)	Length	Tolerance
	MM	Common	High	MM			MM
EN 10216-5 HFD	30≤D≤219.1（D2)	±1.0% or ±0.5mm, whicever is the greater(取较大者)		T1, T≤4	±15% or ±0.6mm, whicever is the greater(取较大者)	L≤6M	+5/0
				T2	±12.5% or ±0.4mm, whicever is the greater(取较大者)
	219.1≤D≤610 (D1)	±1.5% or ±0.75mm, whicever is the greater (取较大者)		T≤0.05D	+22.5%/-15%	6≤12	+10/0
				T1, 0.05D≤0.09D	±15% or ±0.6mm, whicever is the greater(取较大者)
				T2, T>0.09D	±12.5% or ±0.4mm, whicever is the greater(取较大者)	L>12	+by agreement/0
EN 10216-5 CFD	D3(D≤219.1)	±0.75% or ±0.3mm, whicever is the greater(取较大者)		T3	±10% or ±0.2mm, whicever is the greater(取较大者)
	D4(D≤219.1)	±0.5% or ±0.mm, whicever is the greater(取较大者)		T4	±7.5% or ±0.15mm, whicever is the greater(取较大者)
ASTM A213 HFD	D≤100	+0.4/-0.8		D<100,S≤2.4	+40%/0	HFD, all size	+5.0/0
		+0.4/-1.2		D<100,2.4≤3.8	+35%/0
		+0.4/-1.6		D<100,3.8≤4.6	+33%/0
				D<100,S>4.6	+28%/0
	100≤200	+0.4/-1.2		D>100, 2.4≤3.8	+35%/0
	200≤225	+0.4/-1.6		D>100,3.8≤4.6	+33%/0
				D>100,S>4.6	+28%/0
ASTM A213 CFD	D<25	±0.10		D≤38.1	+20%/0	CFD, D<50.8	+3.0/0
	25≤D≤40	±0.15
	40	±0.20
	50≤D<65	±0.25
	65≤D<75	±0.30		D>38.1	+22%/0	CFD, D≥50.8	+5.0/0
	75≤D≤100	±0.38
	100≤200	+0.38/-0.64
	200≤225	+0.38/-1.14
ASTM A269	D≤13	±0.13		D≤13	±15%	D<38	+3.2/0
	13	±0.13		13	±10%
	38≤D<89	±0.25				D>38	+4.8/0
	89≤D<140	±0.38
	140≤D<203	±0.76
	203≤D<305	±1.01
	305≤D<356	±1.26
ASTM A270	D<25	±0.13		For weld pipe all size	±12.5%		+3.0/0
	25-50	±0.20
	50-75	±0.25
	75-100	±0.38		For CD SMLS pipe D≤38.1	+20%/0
	100-140	±0.38					+5.0/0
	140-200	±0.75		For CD SMLS pipe D>38.1	+22%/0
	200-300	±1.25

Precision OD / ID measurement
Wall thickness inspection
Surface roughness testing (Ra)

These inspections guarantee that TP304L stainless steel seamless tubing meets ASTM and international quality standards.

Common Industrial Applications

Pharmaceutical and Biotechnology

WFI and purified water distribution tubing
Clean-steam and CIP system piping
Fermentation and bioreactor transfer lines

Food and Beverage Processing

Product transfer and processing tubing
Dairy and brewery hygienic circuits
CIP and SIP system pipework

Chemical Processing

Dilute organic and inorganic acid service
Solvent and process liquor lines
Heat exchanger and condenser tubing

Oil, Gas and Power

Instrumentation and impulse lines
Steam and condensate tubing
Low-temperature utility service

Quality Assurance and Manufacturing Process

Certification and Documentation

All TP304L tubes are supplied to ASTM A213 / A269 with EN 10204 3.1 mill test certificates. NACE MR0175 / ISO 15156 compliance, PMI reports and full heat-number traceability are available on request.

Non-Destructive Testing (NDT)

Hydrostatic or eddy-current testing is performed on 100% of tubes. Ultrasonic testing (UT) and dye-penetrant inspection (PT) can be supplied for critical service, with records retained for each production lot.

Mechanical and Metallurgical Testing

Tensile, yield, elongation and hardness tests are carried out per heat. Intergranular corrosion testing per ASTM A262 Practice E and microstructure examination are available for welded or sensitisation-critical applications.

Dimensional and Surface Inspection

Outside diameter, wall thickness, ovality and straightness are measured against ASTM A1016 / A1016M. Internal and external surfaces are visually inspected for defects, and surface roughness can be verified for hygienic service.

TP304 vs TP304L – Technical Comparison

TP304L and TP304 share the same 18% chromium / 8% nickel austenitic base, so their general corrosion behaviour and mechanical properties are very close. The decisive difference is carbon content, and it shows up after welding rather than in the mill test certificate.

Chemical Composition

Carbon: TP304L ≤ 0.030 % vs TP304 ≤ 0.080 %
Chromium: both 18.0–20.0 %
Nickel: TP304L 8.0–12.0 % vs TP304 8.0–10.5 %
Molybdenum: none in either grade

Mechanical Properties

Tensile strength: TP304 ≥ 515 MPa vs TP304L ≥ 485 MPa
Yield strength (0.2 %): TP304 ≥ 205 MPa vs TP304L ≥ 170 MPa
Elongation: both ≥ 35 %
TP304L compensates for its lower annealed strength by work-hardening readily during cold drawing

Corrosion and Fabrication

TP304L resists intergranular corrosion in the heat-affected zone after welding without post-weld solution annealing
TP304 is preferred where higher annealed strength is required and welded joints will be annealed
Both are limited in chloride service, where pitting and stress corrosion cracking resistance remains modest

Selection Guidance

Choose TP304L for welded assemblies, heavy-section welding and equipment that cannot be post-weld annealed
Choose TP304 where maximum annealed strength matters and welding is light or followed by annealing
For chloride-bearing service, step up to TP316 / TP316L or a duplex grade

Frequently Asked Questions

What is the difference between TP304 and TP304L?

TP304L contains lower carbon content, which prevents carbide precipitation during welding and improves corrosion resistance in the heat-affected zone.

What standards apply to TP304L seamless tubes?

The most common standards are ASTM A213, ASTM A269, and ASTM A312.

Is TP304L suitable for high-pressure applications?

Yes. Because of its seamless construction, TP304L tubing offers higher pressure resistance compared to welded tubes.

What industries commonly use TP304L tubes?

Major industries include oil & gas, chemical processing, pharmaceuticals, food processing, and aerospace.