SS 304H Seamless Pipes are manufactured using high-carbon austenitic SS containing a rough percentage of chromium of between 18 and 20 and nickel of between 8 and 11, again other than the stainless steel 304/304L grade. This allows strength and high-temperature stability in high-temperature and corrosive conditions in this moderated chemical mix. Chromium provides oxidation and low amounts of corrosion-resistant quality, and nickel provides toughness and ductility. The continuous construction also implies that the buildings are monochromatic and eliminate the weld lines, which are filled with weaknesses, and this implies that the pipes are capable of supporting important services. SS 304H seamless pipes are suitable in applications where high temperature is needed; they possess good mechanical properties as well as the capability of handling pressure easily. This increased carbon increases the creep resistance, which allows the pipes to perform in continuous and discontinuous activities at high temperatures. They are also good in weldability, machinability, and formability; hence, the fabrication can be made easy without affecting the performance. The pipes are smooth inside and share the same wall thickness, and hence, the pipes are very effective in the flow of fluids and durability.
The pipes are normally suitable in boilers, heat exchangers, power generation plants, refineries, petrochemical units, and pressure vessels, where strength and temperature resistance are of paramount importance. The sizes, wall thicknesses, lengths, and finishes on the end of SS 304H smooth pipes vary, and the finishes are plain finish, bevelled, or threaded. The pipes are inspected and subjected to tests as per the standard in the industry in order to conform to the dimensional accuracy, the mechanical strength and the levels.
Table of Content
- SS 304H Seamless Pipe Specifications
- High-Temperature Properties of SS 304H Welded Pipe
- Chemical Composition of SS 304H Seamless Pipe
- ASME SA312 SS TP304H Seamless Pipes Mechanical Properties
- Physical Properties of SS 304H SS
- Manufacturing Process of SS 304H Seamless Pipes
- SS 304H Seamless Pipe Sizes Chart
- SS 304H Seamless Pipe Dimension Chart
- Stainless Steel UNS S30409 Seamless Pipes Equivalent Grades
- SS 304H vs 304 vs 304L Pipes
- Advantages of SS 304H Seamless Pipes
- Applications of SS 304H Seamless Pipes
- Why Choose Metinox Overseas?
- Frequently Asked Questions (FAQ)
SS 304H Seamless Pipe Specifications
| Specification | Details |
| Material Grade | SS 304H / UNS S30409 / WNR 1.4948 |
| Standard | ASTM A312, ASME SA312 |
| Outside Diameter (OD) | 1/8" to 12" NPS (6.35 mm to 114.3 mm for specific round pipes) |
| Wall Thickness (WT) | 0.6 mm to 12.7 mm |
| Schedule | SCH 5 to SCH XXH |
| Length | Single Random, Double Random |
| Technique | Cold Formed, Precision Rolled, Hot Formed |
| Manufacturing Process | Seamless, ERW, Welded, Fabricated |
| Ends | Plain End, Beveled End |
| Finish Options | Polished, Bright, Annealing, Mirror |
| Testing Protocols | Chemical, Mechanical, Ultrasonic, PMI (Positive Material Identification) |
| Origin | India, Europe, Japan, South Korea |
High-Temperature Properties of SS 304H Welded Pipes
| Temperature (-C) | Temperature (-F) | Yield Strength (MPa) | Tensile Strength (MPa) |
| Room Temp | 68 | 205 | 515 |
| 100 | 212 | 170 | 450 |
| 300 | 572 | 125 | 400 |
| 500 | 932 | 105 | 385 |
| 600 | 1112 | 95 | 315 |
| 700 | 1292 | 85 | 215 |
| 800 | 1472 | 75 | 135 |
Chemical Composition of SS 304H Seamless Pipes
| Element | Symbol | Composition (Wt. %) |
| Carbon | C | 0.04 - 0.10 |
| Manganese | Mn | 2.00 max |
| Silicon | Si | 0.75 max |
| Phosphorus | P | 0.045 max |
| Sulfur | S | 0.030 max |
| Chromium | Cr | 18.0 - 20.0 |
| Nickel | Ni | 8.0 - 10.5 |
| Molybdenum | Mo | 0.00 |
| Nitrogen | N | 0.00 |
ASME SA312 SS TP304H Seamless Pipes Mechanical Properties
| Grade | Tensile Strength (MPa) min | Yield Strength 0.2% Proof (MPa) min | Elongation (% in 50mm) min | Hardness Rockwell B (HR B) max | Hardness Brinell (HB) max |
| SS 304H | 515 | 205 | 40 | 92 | 201 |
Physical Properties of SS 304H Seamless Pipes
| Electrical Resistivity (n-m) | Density (kg/m3) | Thermal Expansion (m/m/∘C) | Specific Heat (J/kg⋅K) | Thermal Conductivity (W/m⋅K) | Elastic Modulus (GPa) |
| 720 | 8000 | 0-538°C: 18.4 0-315°C: 17.8 0-100°C: 17.2 |
500 | at 500°C: 21.5 at 100°C: 16.2 |
193 |
Manufacturing Process of SS 304H Seamless Pipes
The manufacturing process of SS 304H seamless pipes is clearly laid down and regulated in order to provide high strength and stability to the pipes to be used in high-temperature applications.
Raw Material Selection
To achieve the correct chemical composition, strength, and heat resistance in the right way anticipated by the standards of SS 304H, billets of high-carbon SS are acquired in the ISO-certified mills.
Billet Heating & Piercing
The billets are welded at high temperatures and punched into hollow tubes and have no weld fissures that ensure high structural integrity and uniformity.
Mandrel Drawing & Sizing
The hollow pipes are drawn over the mandrels to achieve the desired outer diameter, wall thickness and length with reference to ASTM standards.
Solution Heat Treatment
Pipes are subjected to controlled heat treatment to increase strength at high temperature levels and stabilise the microstructure, as well as to improve the overall performance of the pipes.
Pickling & Passivation
Pickling is followed by removal of the surface oxides, and passivation is then carried out to enhance the corrosion strength and cleanliness of the surface.
Dimensional and Surface Inspection
The pipes are inspected in regard to diameter, thickness, straightness, and surface finish through the inspection of all the pipes to ensure compliance with ASTM A312 TP304H.
Pressure Testing and Non-Destructive Testing
To ensure that the product works without any defects, the tests are undertaken under extreme pressure, and ultrasonic, eddy current and hydrostatic pressure tests are conducted.
International Dispatch and Certification
They are packed in order to export to the USA, Europe, the Middle East and LATAM and provide complete traceability in the form of Mill Test Certificates (EN 10204 3.1).
SS 304H Seamless Pipe Sizes Chart
| Wall Thickness (WT) | Sizes (Diameter) |
| .375 | 3 1/2" |
| .250 | 3" |
| .134 | 1" |
| .125 | 3/4", 1 1/4", 2", 3", 3 1/4" |
| .120 | 1/2", 5/8", 7/8", 1", 1 1/4", 1 1/2", 2", 2 1/4", 2 1/2", 3" |
| .109 | 1/2", 1", 1 1/4", 1 1/2", 2" |
| .095 | 1/2", 5/8", 1", 1 1/2", 2" |
| .083 | 1/4", 5/8", 3/4", 7/8", 1", 1 1/4", 1 5/8", 1 7/8", 2 1/2", 3" |
| .065 | 1/4", 3/8", 1/2", 5/8", 7/8", 1", 1 1/2", 1 5/8", 1 3/4" |
| .049 | 3/16", 5/16", 5/8", 3/4", 1", 1 1/8", 1 5/8", 2", 2 1/4" |
| .035 | 1/8", 1/4", 3/8", 7/16", 1/2", 5/8", 1 1/4", 1 1/2", 1 5/8", 2" |
| .028 | 3/16", 1/4", 5/16", 3/8", 1/2", 3/4", 1", 1 1/2", 2" |
| .020 | 1/16", 1/8", 1/4", 5/16", 3/8" |
| .016 | 1/8", 3/16" |
| .012 | 1/8" |
| .010 | 1/16", 1/8", 3/16" |
SS 304H Seamless Pipe Dimension Chart
| NPS (DN) | Weight (kg/m) | SCH | OD (mm) | ID | WT (mm) |
| 32 | 126.032 | 0.00 | 813 | 0.00 | 6.035 |
| 34 | 134.031 | 0.00 | 864 | 0.00 | 6.035 |
| 36 | 142.014 | 0.00 | 914 | 0.00 | 6.035 |
| 38 | 186.094 | 0.00 | 965 | 0.00 | 7.092 |
Stainless Steel UNS S30409 Seamless Pipes Equivalent Grades
| Property | Value (Minimum) |
| Tensile Strength | 515 MPa (75,000 psi) |
| Yield Strength (0.2% Proof) | 205 MPa (30,000 psi) |
| Elongation (in 50mm) | 40% |
| Hardness (Brinell) | 201 HB Max |
| Hardness (Rockwell B) | 92 HRB Max |
SS 304H vs 304 vs 304L Pipes Comparison
| Feature | Grade 304 (Standard) | Grade 304L (Low Carbon) | Grade 304H (High Carbon) |
| UNS Designation | S30400 | S30403 | S30409 |
| Carbon (%) | =0.08 | =0.03 | 0.04 - 0.10 |
| Tensile Strength (min) | 515 MPa | 485 MPa | 515 MPa |
| Yield Strength (min) | 205 MPa | 170 MPa | 205 MPa |
| Max Service Temp | ~425°C (continuous) | ~425°C | Up to 815°C (1500°F) |
| Weldability | Good | Excellent (No Annealing) | Fair (Risk of Sensitization) |
| Primary Advantage | Versatile General Purpose | Best for Welding/Corrosion | Best for High Heat Strength |
Advantages of SS 304H Seamless Pipes
The SS 304H Seamless Pipe is associated with a lot of advantages, some of which include the following:
High-Temperature Strength
The superior amount of carbon in SS 304H offers good strength and stability at high temperatures, and is thus applicable in the heat-sensitive applications.
Seamless Construction
The seamless weld joints enhance the structural integrity and minimize chances of leakage or collapse due to high pressure.
Good Corrosion Resistance
The levels of chromium and nickel provide good resistance against oxidation and low corrosive conditions.
Excellent Pressure Handling
The standardized thickness of the walls allows these pipes to stand under high internal pressure and mechanical stress.
Good Weldability and Fabrication
SS 304H seamless pipes are easily welded and molded, and mechanical strength is not lost.
Long Service Life
Good mechanical characteristics and thermal fatigue resistance give the products longevity in harsh environments.
Applications of SS 304H Seamless Pipes
This material is mostly applied in industries with high temperatures and power plants, although there are some of the most common industries that apply this material, depending on their needs.
Power Generation Plants
Used in boilers, superheaters and high-temperature heat recovery plants.
Oil & Gas Industry
It may be utilised in the piping systems of refineries and processing units in high-pressure and high-temperature environments.
Plants, Petrochemical, and Chemical
They are able to deal with hot process fluids, gases and hostile working conditions.
Heat Exchangers & Boilers
They are also famous in high-creep components and heat-stable components.
Pressure Vessels
Used in the pressure-retaining equipment that is of utmost importance due to its immense power and steadiness.
Why Choose Metinox Overseas?
Here are some key reasons to choose Metinox Overseas for SS 304H Seamless Pipes:
- Manufactured in ISO 9001:2015 certified mills for consistent quality
- Expertise in high-performance SS 304H seamless pipes for industrial use
- Wide range of sizes, schedules, and custom lengths available
- Pipes designed to withstand high temperature and pressure applications
- Strict testing, including PMI, hydrostatic, and non-destructive inspections
- Reliable export to the USA, Europe, the Middle East, LATAM, and Asia
- Durable packaging ensuring safe delivery to global clients
- Dedicated support with technical guidance and competitive pricing
Looking for High-Quality SS 304H Seamless Pipes?
Choose Metinox Overseas - Your Reliable Stainless Steel Pipe Manufacturer & Exporter.
Let us support your projects with quality, precision, and performance.
Frequently Asked Questions (FAQ)
The 304H SS has a higher carbon content than 304, giving it better strength at high temperatures while maintaining similar corrosion resistance.
It is used in high-temperature, high-pressure applications like boilers, heat exchangers, chemical processing, and power plants.
The composition of SS 304H typically contains 18-20% chromium, 8-10% nickel, and 0.04-0.10% carbon, along with small amounts of manganese, silicon, and phosphorus.
Many industries use this material according to their usage, that include power generation, chemical and petrochemical, oil and gas, food processing, pharmaceuticals, and water treatment.
Yes, SS 304H is ideal for high-temperature applications due to its excellent strength and stability at elevated temperatures.
Other Types of Seamless Pipes
stainless steel 310h seamless pipe, stainless steel 316 316l seamless pipe, stainless steel 316ti seamless pipe, stainless steel 317 317l seamless pipe, stainless steel 321 321h seamless pipe, stainless steel 347 347h seamless pipe, stainless steel 904l seamless pipe, Stainless Steel 304H Seamless Pipe Gauges, Seamless Stainless Steel 304H Pipes Manufacturer in Mumbai, SS 304H Seamless Pipe exporter in India, schedule 80 Stainless Steel 304H Seamless Pipes, Stainless Steel 304H Large Diameter Seamless Pipe, ASTM A312 304H Stainless Steel Seamless Pipe, Seamless Stainless Steel UNS S30409 Pipe, SS 304H schedule 10 Seamless Pipe, Thick Walled Stainless Steel 304H Seamless Pipe Stockists in India, SS 304H Seamless Pipe Price List, Grade 304H Seamless Pipes, 304H Stainless Steel schedule 160 Seamless Pipes, SS 304H Seamless Pipe Distributor, 304H SS schedule 40/40S Seamless Pipe Supplier in India
Supplier and Exporter of Stainless Steel 304H Seamless Pipes in Cities
Thiruvananthapuram, Chandigarh, Montreal, Hong Kong, La Victoria, Madrid, Singapore, Moscow, Ernakulam, Edmonton, Ahmedabad, Tehran, Ludhiana, Bengaluru, Milan, Kanpur, Seoul, Sharjah, Haryana, Granada, Colombo, Riyadh, Geoje-si, Al Jubail, Istanbul, Ranchi, Melbourne, Los Angeles, Atyrau, Kuwait City, Busan, Brisbane, Dallas, Coimbatore, Ahvaz, Dammam, Gimhae-si, Navi Mumbai, Hyderabad, Hanoi, Perth, Kuala Lumpur, London, Toronto, Rajkot, Abu Dhabi, Bangkok, Santiago, Pune, Courbevoie, Mexico City, Faridabad, Karachi, Nagpur, Chennai, Thane, Dubai, Noida, Visakhapatnam, Nashik, New Delhi, Caracas, Aberdeen, Manama, Howrah, Doha, Ankara, Al Khobar, Lahore, Pimpri-Chinchwad, Baroda, Kolkata, Rio de Janeiro, Lagos, Sydney, Mumbai, Algiers, Calgary, Petaling Jaya, Surat, Indore, Bhopal, Jeddah, Port-of-Spain, Vung Tau, Ho Chi Minh City, Jaipur, Vadodara, New York, Jakarta, Gurgaon, Ulsan, Bogota, Cairo, Secunderabad, Jamshedpur, Muscat, Houston, Chiyoda.
Supplier and Exporter of Stainless Steel 304H Seamless Pipes in Countries
Singapore, Denmark, Belarus, Estonia, United Kingdom, Taiwan, Afghanistan, Bahrain, Bulgaria, Romania, Tunisia, Mongolia, United States, Gabon, Nepal, Norway, Germany, Iran, Bhutan, Trinidad & Tobago, Lebanon, Netherlands, Libya, Greece, Oman, Switzerland, Austria, Costa Rica, South Africa, Nigeria, Nigeria, Hungary, South Korea, Morocco, Algeria, Chile, Ghana, Pakistan, Serbia, Chile, Namibia, Ireland, Zimbabwe, Brazil, Tibet, Malaysia, Turkey, Thailand, Spain, Kuwait, Azerbaijan, Sweden, Canada, Ecuador, Hong Kong, Peru, Australia, Belgium, Russia, Egypt, Israel, Jordan, Kenya, Italy, Philippines, Mexico, India, Japan, Venezuela, Czech Republic, Sri Lanka, Indonesia, Angola, Colombia, Bangladesh, Croatia, France, Iran, China, Argentina, Puerto Rico, Bolivia, Qatar, Yemen, Lithuania, Mexico, Saudi Arabia, Gambia, United Arab Emirates, Ukraine, Slovakia, Poland, Macau, Iraq, Kazakhstan, New Zealand, Portugal, Finland, Poland, Vietnam.
Related Stainless Steel Products
Enquire Now
Get pricing within 24 hours!
