TP304 Seamless Stainless Steel Pipe

UNS S30400|1.4301|TP304 Seamless Stainless Steel Pipe

UNS S30400|1.4301|TP304 Seamless Stainless Steel Pipe
Seamless Stainless Steel TP304 Pipes (UNS S30400) are high-integrity cylindrical solutions engineered from the most versatile and widely used austenitic stainless steel grade. As a premier manufacturer based in Wenzhou, China, XinZhe produces precision-engineered seamless piping that strictly complies with ASTM A312, ASME SA312, and DIN 17458 standards.

Our TP304 seamless pipes offer exceptional corrosion resistance and mechanical strength, making them indispensable for chemical processing, oil & gas, and high-pressure construction projects. Known for its superior formability and weldability, our 304 stainless steel tubing is also a reliable choice for the food and beverage industry, ensuring long-lasting performance and hygienic integrity. Through advanced cold-drawing and vacuum annealing, XinZhe guarantees tight dimensional tolerances and a superior surface finish for every order.
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What Is a Seamless Stainless Steel TP304 Pipe?

Seamless Stainless Steel TP304 Pipe – Versatile Corrosion-Resistant Austenitic Stainless Steel Pipe

ASeamless Stainless Steel TP304 Pipe is a high-quality industrial pipe manufactured from a solid stainless steel billetusinghot extrusion or cold drawing processes. Unlike welded pipes, seamless pipes contain no longitudinal weld seams, ensuring a uniform metallurgical structure and superior mechanical reliability.

Key Features and Technical Advantages

Under the ASTM A312 specification, TP304 (Type 304 Stainless Steel) is an austenitic chromium-nickel alloy widely recognized as the most commonly used stainless steel grade worldwide.

The alloy typically contains 18% chromium and 8% nickel, often referred to as 18/8 stainless steel. This composition provides excellent corrosion resistance, weldability, formability, and oxidation resistance, making ASTM A312 TP304 seamless pipes suitable for a wide range of industrial applications.

Because of its balanced performance and cost efficiency, 304 stainless steel seamless pipe has become the industry standard material for general corrosion-resistant piping systems.

Choosing Seamless TP304 Stainless Steel Pipe provides several important engineering benefits compared with welded alternatives.

Excellent Corrosion Resistance

The high chromium-nickel content forms a stable passive oxide layer on the steel surface, providing strong resistance to oxidation, atmospheric corrosion, moisture, and a wide range of organic and inorganic chemicals.

Higher Pressure Capability

Because seamless pipes do not contain weld seams, they eliminate the weld efficiency factor typically applied to welded pipes, allowing for higher allowable working pressures and improved operational safety.

Uniform Mechanical Properties

The absence of a heat-affected zone (HAZ) ensures consistent tensile strength, yield strength, and hardness across the entire pipe wall.

Hygienic Internal Surface

The smooth internal bore of TP304 seamless tubing minimizes bacterial growth, scale formation, and sediment buildup, which is essential for sanitary processing systems.

Excellent Low-Temperature Toughness

Austenitic stainless steel maintains high impact toughness and ductility at cryogenic temperatures, making it suitable for low-temperature and LNG applications.

The superior properties of TP304 stainless steel are a direct result of its precisely controlled chemical composition. Below are the typical elemental content ranges for this grade:

Mechanical properties are key indicators of how a material behaves under various forces. These figures directly relate to the strength, ductility, and overall resilience of TP304 seamless pipes.

Physical properties dictate a material's inherent characteristics under different environmental conditions, such as density, melting point, and thermal conductivity.

Product Specifications and Data

Chemical Composition

GradeCSiMnCrNiSP
304≤ 0.08≤1.00≤2.0018.00-20.008.00-11.00≤0.03≤0.045
304L≤0.035≤1.00≤2.0018.00-20.008.00-13.00≤0.03≤0.045
304H0.04-0.10≤1.00≤2.0018.00-20.008.00-11.00≤0.03≤0.045

Typical Mechanical Properties

MaterialTensile Strength ksi(MPa)Yield Strength ksi(MPa)Elongation (%)Hardness Brinell/VickersHardness Rockwell
304≥75(515)≥30(205)≥ 35≤192HBW/200HV≤90HRB
304L≥70(485)≥25(170)≥ 35≤192HBW/200HV≤90HRB
304H≥75(515)≥30(205)≥ 35≤192HBW/200HV≤90HR

Typical Physical Properties

DensityMelting PointThermal ExpansionThermal ConductivityModulus of ElasticityElectrical Resistivity
8.0 g/cm³1400-1450 ℃17.2 µm/m·℃16.2 W/m·K193 GPa0.72 µΩ·m

Dimensional Standards and Tolerances

StandardOD(D)Tolerance （MM)Thickness(S)Tolerance(MM)LengthTolerance
MMCommonHighMMMM
ASTM A312D ≤48.3+0.4/-0.810.3 ≤73+20%-12.5%+6.0/0
48.3 ≤114.30±0.888.9 ≤457.2,t/D ≤5%+22.5%/-12.5%
114.3 ≤219.1+1.6/-0.888.9 ≤457.2,t/D >5%+15%/-12.5%
219.1 ≤457.2+2.4/-0.8D ≥508, t/D≤5%,SMLS+22.5%/-12.5%
457.2 ≤660.4+3.2/-0.8D ≥508, t/D>5%,SMLS+15%/-12.5%
660.4 ≤863.6+4.0/-0.8D ≥508, WELD+17.5%/-12.5%
863.6 ≤1219.2+4.8/-0.8
JIS 3459 Hot-Finished Smls PipeD ＜50±0.51S ＜4±0.5
D ≥50±1.0%S ≥4±12.5%
JIS 3459 Cold-FinishedD ＜30±0.3S ＜2±0.2
D ≥30±1.0%S ≥2±10.0%
JIS G3463 Hot-Finished Smls Pipe100+0.4/-0.8D ＜100， S/D+7/0
D ＜100， 2≤S+40%/0D+10/0
D ＜100， 2.4≤S+35%/0
D ＜100， 3.8≤S+33%/0
D ＜100， 4.6≤S+28%/0D+13/0
100 ≤D+0.4/-1.2D>100, S ＜2/
120 ≤DD>100 ， 2≤S/D+15/0
160 ≤D+0.4/-1.8D>100 ， 2.4≤S+35%/0
200 ≤D+0.4/-2.4D>100 ， 3.8≤S+33%/0D>50,7+10/0
D>100 ， 4.6≤S+28%/0
JIS G3463 Cold-finished+0.4/-0.8D+0.4/0
60 ≤D±0.3D ≥2.0+20%/0D>50,7+13/0
80 ≤D±0.4D ≥40+22%/0
100 ≤D+0.4/-0.6
120 ≤D+0.4/-0.8D>50,10M+15/0
160 ≤D+0.4/-1.2
200 ≤D+0.4/-1.6
GB/T 14975 冷拔(扎)钢管D±0.3±0.1所有壁厚，普通级PA+12.5%/-10%
12.7±0.15
38.1±0.4±0.3
88.9±0.9%±0.4
139.7±0.8所有壁厚，高级PC±10%
203.2±1.1
219.1±1.6
D ≥323.9±0.5%
GB/T 14976 冷拔(轧)钢管6±0.2±0.15S ≤3±12%(10% /0 高级PC)
10 ≤D±0.2±0.2
30 ≤D±0.2±0.3S>3+12.5%/-10%(10%/0 高级PC)
50 ≤D0.85%0.75%
D>2190.9%0.8%Smin, all+22%/0(+20%/0 高级PC)

Common Industrial Applications

Due to its versatility and compliance with ASME and ASTM standards, TP304 seamless stainless steel pipe is widely used across multiple industries.

Oil & Gas and Petrochemical Industry

  • Instrumentation tubing
  • Low-pressure process piping
  • Heat exchanger systems
  • Corrosion-resistant fluid transport lines

Food and Beverage Processing

  • Breweries and beverage production lines
  • Dairy processing equipment
  • Liquid food transport systems

Pharmaceutical and Biotechnology

  • Purified Water (PW) systems
  • Water for Injection (WFI) systems
  • Sterile process piping

Chemical Processing Industry

  • Mild acids
  • Alkalis
  • Chemical solvents
  • Process fluids requiring corrosion resistance

Architectural and Structural Applications

  • Handrails and balustrades
  • Structural support systems
  • Decorative and architectural tubing

Quality Assurance and Manufacturing Process

To guarantee consistent quality and full traceability, all Seamless TP304 Stainless Steel Pipes are supplied with comprehensive testing and certification documentation.

Every TP304 seamless pipe undergoes strict quality control from billet selection through forming, heat treatment and final inspection:

Certification

  • EN 10204 3.1 / 3.2 Material Test Certificates (MTC) issued for every heat
  • Compliance with ASTM A312 / ASME SA312 and ASTM A213 / ASME SA213
  • Full heat traceability from raw material to finished pipe

Non-Destructive Testing (NDT)

  • Ultrasonic Testing (UT) per ASTM E213
  • Eddy Current Testing (ET) for surface and near-surface defects
  • Hydrostatic pressure testing to verify pipe integrity

Material Verification

  • 100% Positive Material Identification (PMI)
  • Chemical analysis confirming composition against the specified grade
  • Carbon and sulfur analysis where required

Mechanical Testing

  • Tensile, yield and elongation testing per ASTM A370
  • Hardness testing to confirm the specified condition
  • Flattening, flaring and intergranular corrosion tests

Dimensional Inspection

  • OD, wall thickness and ovality verified against the tolerance table
  • Length, straightness and end preparation checked before dispatch
  • Third-party inspection available through ABS, DNV, BV, TUV or SGS

TP304 vs TP304L / TP304H – Technical Comparison

TP304 (UNS S30400) is the base austenitic 18-8 stainless steel grade and remains the most widely specified pipe material in the world. TP304L and TP304H are the low-carbon and high-carbon derivatives developed for welding and elevated-temperature service respectively.

Chemical and Metallurgical Differences

  • Carbon content: TP304 specifies 0.080% max, TP304L 0.030% max, and TP304H 0.040–0.100%.
  • Chromium and nickel: TP304 contains 18.00–20.00% Cr and 8.00–11.00% Ni, giving the classic 18-8 austenitic structure.
  • Sulfur and phosphorus: All grades limit S to 0.030% and P to 0.045% max for consistent hot working.
  • Sensitization: The higher carbon of TP304 makes it susceptible to chromium carbide precipitation in the 425–815°C range.

Mechanical Properties Comparison

  • Tensile strength: TP304 requires 515 MPa (75 ksi) minimum while TP304L requires 485 MPa (70 ksi).
  • Yield strength: TP304 requires 205 MPa (30 ksi) minimum versus 170 MPa (25 ksi) for TP304L.
  • Elevated temperature: TP304 performs better than TP304L above 425°C but is inferior to TP304H for long-term creep service.
  • Short-time strength: The higher carbon of TP304 gives it a modest advantage in short-time high-temperature strength.

Corrosion and Welding Behaviour

  • Weldability: TP304 welds readily, but heavy sections may require solution annealing to restore intergranular corrosion resistance.
  • Intergranular corrosion: In as-welded condition TP304L is markedly superior; specify TP304L whenever post-weld heat treatment is impractical.
  • General corrosion: Both grades behave identically in atmospheric, fresh water, nitric acid and most oxidizing media.
  • Cost position: TP304 is generally the least expensive of the three grades by a small margin.

Selection Guide

  • ChooseTP304 for general corrosion-resistant piping where welding is limited or post-weld annealing is available.
  • ChooseTP304L for welded systems and any application where intergranular corrosion resistance is critical.
  • ChooseTP304H for high-temperature service above 525°C.

Frequently Asked Questions

What is TP304 seamless pipe?

TP304 (UNS S30400) is the basic 18-8 austenitic stainless steel seamless pipe containing 18.00–20.00% Cr and 8.00–11.00% Ni with a maximum carbon content of 0.080%. It is the most widely used corrosion-resistant pipe grade in general industry.

What is the difference between TP304, TP304L and TP304H?

The three grades differ mainly in carbon content: TP304 allows up to 0.080%, TP304L is limited to 0.030% for welding resistance, and TP304H specifies 0.040–0.100% for improved elevated-temperature creep strength.

What standard covers TP304 seamless pipe?

TP304 seamless pipe is manufactured to ASTM A312 / ASME SA312 for general service, ASTM A213 / ASME SA213 for heat-exchanger tubing and ASTM A269 for instrumentation tubing. EN 10216-5 and JIS G3459 provide the European and Japanese equivalents.

What is TP304 pipe used for?

TP304 is used for water and wastewater piping, food and dairy processing, chemical and petrochemical lines, architectural and structural tubing, heat exchangers and general corrosion-resistant industrial piping.

Ready to Request a Quotation?

Send your Seamless Stainless Steel TP304 Pipe enquiry with grade, applicable ASTM/ASME standard and edition, OD × wall thickness, length, quantity, end finish, delivery destination and inspection documents — you will get a written quotation stating the specification and edition, delivery condition, documents included and lead time.

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