Stainless Steel 304H Welded Pipes Manufacturer in India

What are Stainless Steel 304H Welded Pipes?

Stainless Steel 304H Welded Pipe is a high-carbon austenitic stainless steel pipe manufactured by forming stainless steel strip or plate into a tubular shape and joining the longitudinal seam by welding. The 304H grade contains chromium and nickel and has a higher carbon content than 304L, providing properties suited to elevated-temperature service.

304H Welded Pipe is used where corrosion resistance, mechanical strength and high-temperature performance are required. It is commonly considered for process piping, heat-related industrial systems, chemical equipment, power generation and other applications where the material must operate under elevated temperatures.

Kamal Steels is a Stainless Steel 304H Welded Pipe Manufacturer and Stockist in India, based in Mumbai. The company supplies 304H welded pipes in different sizes, schedules, wall thicknesses, lengths and finishes according to customer and project requirements.

The commonly specified pressure-piping designation is ASTM A312 TP304H / ASME SA312 TP304H, with UNS designation S30409. Pipes can be supplied with applicable testing, inspection and material documentation according to project requirements.

Stainless Steel 304H Welded Pipe

Table of Contents

Stainless Steel 304H Welded Pipe Specifications

Stainless Steel 304H Welded Pipe is a high-carbon austenitic stainless steel pipe designed for applications requiring good corrosion resistance and enhanced high-temperature strength. The 304H grade is a higher-carbon version of the 304 stainless steel family and is commonly specified for elevated-temperature service.

ASTM A312 TP304H is a commonly specified material designation for 304H stainless steel pipe used in pressure and high-temperature applications. The welded pipes are available in different nominal sizes, schedules, wall thicknesses, lengths and surface conditions according to applicable ASTM, ASME and project requirements.

Specification Details
Product Stainless Steel 304H Welded Pipe
Grade 304H / Type 304H
UNS Number S30409
ASTM Specification ASTM A312
ASME Specification ASME SA312
Material Type Austenitic Stainless Steel
Pipe Type Welded
Manufacturing Process Formed Stainless Steel Strip / Plate with Welded Seam
Nominal Size 1/8 NB to 48 NB and as required
Schedules SCH 5S, SCH 10S, SCH 40S, SCH 80S, SCH 160, XXS and others
Length Single Random, Double Random and Cut Length
End Preparation Plain End, Bevelled End, Threaded End and as required
Surface Finish Annealed & Pickled, Mill Finish, Bright Annealed and Polished
Testing Hydrostatic, Ultrasonic, PMI, Dimensional Inspection and other specified tests
Material Certificate EN 10204 3.1 Certificate available as required

Kamal Steels supplies Stainless Steel 304H Welded Pipes in standard and project-specific sizes, schedules, wall thicknesses and lengths. Testing, inspection, material certification and export packaging can be provided according to applicable standards and customer requirements.

Stainless Steel 304H Welded Pipe Chemical Composition

The chemical composition of Stainless Steel 304H provides the austenitic structure and corrosion resistance associated with the 304 stainless steel family while maintaining a higher carbon level than 304L. Chromium provides the passive oxide layer responsible for stainless steel corrosion resistance, while nickel helps stabilize the austenitic structure.

The controlled carbon content of 304H distinguishes it from the low-carbon 304L grade and makes 304H suitable for specified elevated-temperature applications. The exact chemical requirements should always be verified against the applicable ASTM specification and material test certificate.

Element Composition (%)
Carbon (C) 0.04–0.10
Manganese (Mn) 2.00 max.
Silicon (Si) 1.00 max.
Phosphorus (P) 0.045 max.
Sulfur (S) 0.030 max.
Chromium (Cr) 18.0–20.0
Nickel (Ni) 8.0–11.0
Iron (Fe) Balance

The higher carbon range is an important characteristic of 304H and is one of the reasons the grade is selected for certain elevated-temperature services. Actual composition should be confirmed from the applicable material specification and supplied material test certificate.

Stainless Steel 304H Welded Pipe Sizes, Dimensions & Wall Thickness

Stainless Steel 304H Welded Pipes are available in different nominal pipe sizes, outside diameters and wall thicknesses to meet industrial process and high-temperature piping requirements. The required dimensions are selected according to nominal pipe size, applicable dimensional standards, design pressure, temperature and project requirements.

Pipe wall thickness is commonly identified by schedule. Common schedules include SCH 5S, SCH 10S, SCH 40S, SCH 80S, SCH 160 and XXS, subject to pipe size and availability. Heavier schedules provide greater wall thickness and may be selected where higher mechanical or pressure requirements apply.

Nominal Pipe Size Outside Diameter Common Schedules
1/8 NB 10.3 mm SCH 5S, SCH 10S, SCH 40S, SCH 80S
1/4 NB 13.7 mm SCH 5S, SCH 10S, SCH 40S, SCH 80S
1/2 NB 21.3 mm SCH 5S, SCH 10S, SCH 40S, SCH 80S
1 NB 33.4 mm SCH 5S, SCH 10S, SCH 40S, SCH 80S
1 1/2 NB 48.3 mm SCH 5S, SCH 10S, SCH 40S, SCH 80S
2 NB 60.3 mm SCH 5S, SCH 10S, SCH 40S, SCH 80S
3 NB 88.9 mm SCH 5S, SCH 10S, SCH 40S, SCH 80S
4 NB 114.3 mm SCH 5S, SCH 10S, SCH 40S, SCH 80S
6 NB 168.3 mm SCH 5S, SCH 10S, SCH 40S, SCH 80S, SCH 160
8 NB 219.1 mm SCH 10S, SCH 40S, SCH 80S, SCH 160
10 NB 273.1 mm SCH 10S, SCH 40S, SCH 80S, SCH 160
12 NB 323.9 mm SCH 10S, SCH 40S, SCH 80S, SCH 160
14 NB 355.6 mm SCH 10S, SCH 40S, SCH 80S
16 NB 406.4 mm SCH 10S, SCH 40, SCH 80
18 NB 457.2 mm SCH 10S, SCH 40, SCH 80
20 NB 508.0 mm SCH 10S, SCH 40, SCH 80
24 NB 610.0 mm SCH 10S, SCH 40, SCH 80

Kamal Steels supplies Stainless Steel 304H Welded Pipes in standard and custom sizes, schedules, wall thicknesses and lengths according to applicable standards, customer drawings and project specifications.

ASTM A312 TP304H Welded Pipe Dimensions & Tolerances

ASTM A312 TP304H Welded Pipes are manufactured with controlled dimensional requirements for outside diameter, wall thickness, length and other applicable dimensions. Maintaining dimensional consistency is important for pipe fit-up, welding, fabrication and installation in industrial piping systems.

Parameter Requirement
Outside Diameter Controlled according to applicable ASTM A312 dimensional requirements and specified pipe size.
Wall Thickness Controlled according to the specified nominal thickness and applicable standard requirements.
Length Available in standard random, double random or specified cut lengths.
Ovality Controlled to maintain acceptable pipe roundness and dimensional consistency.
End Preparation Plain, bevelled or other specified end preparation.

Dimensional inspection can be performed to verify outside diameter, wall thickness, length and other applicable requirements. For critical projects, additional inspection and testing can be specified by the purchaser.

Kamal Steels supplies ASTM A312 TP304H Welded Pipes according to applicable dimensional requirements with options for specified sizes, schedules, wall thicknesses, lengths, testing and material certification.

Stainless Steel 304H Welded Pipe Pressure Rating

The pressure capability of Stainless Steel 304H Welded Pipe depends on pipe outside diameter, wall thickness, operating temperature, allowable material stress and the applicable piping design code. The 304H grade is often selected for elevated-temperature service, but the maximum allowable working pressure must be established from the complete design conditions.

Factor Effect on Pressure Design
Pipe Size Outside diameter is considered in pressure design calculations.
Wall Thickness A thicker wall generally provides greater pressure carrying capability.
Pipe Schedule Different schedules provide different nominal wall thicknesses.
Operating Temperature Allowable material stress changes with service temperature.
Design Code The applicable piping code determines the design methodology and allowable stresses.
Corrosion Allowance Additional wall thickness may be required where corrosion or erosion is expected.

For high-temperature and pressure-service applications, the required wall thickness and allowable pressure should be determined through project-specific engineering calculations. The applicable ASTM, ASME and piping design requirements should be confirmed before selecting the final pipe schedule.

Stainless Steel 304H Welded Pipe Equivalent Grades

Stainless Steel 304H is identified by different designations under international material systems. These designations assist procurement teams, engineers and manufacturers when identifying the material across different standards.

Standard 304H Designation
ASTM 304H
ASME SA312 TP304H
UNS S30409
EN 1.4948

Equivalent designations should not automatically be treated as interchangeable for every application. Chemical composition, mechanical properties, heat treatment, manufacturing requirements, testing and applicable code requirements should be verified before material substitution.

Stainless Steel 304H Welded Pipe Surface Finish

The surface finish of Stainless Steel 304H Welded Pipe is selected according to manufacturing requirements and the intended application. Industrial piping generally uses standard mill or annealed and pickled conditions, while specialized applications may require brighter or polished surfaces.

Surface Finish Description Typical Application
Annealed & Pickled Heat-treated and chemically cleaned surface. Industrial process piping
Mill Finish Standard surface obtained during manufacturing. General industrial applications
Bright Annealed Bright and smooth surface produced by controlled annealing. Process and specialized applications
Polished Mechanically finished surface with improved smoothness. Food, pharmaceutical and specialized applications

The required surface condition should be specified according to the operating environment, cleaning requirements, fabrication process and final application. Kamal Steels can supply 304H Welded Pipes with the specified surface condition according to customer and project requirements.

Stainless Steel 304H Welded Pipe Applications

Stainless Steel 304H Welded Pipes are used in applications where corrosion resistance and elevated-temperature performance are important. The grade is particularly considered for industrial systems operating at temperatures where the higher-carbon 304H composition is appropriate.

Application Typical Use
High-Temperature Process Piping Process lines operating at elevated temperatures
Power Generation Selected high-temperature piping and utility systems
Chemical Processing Process piping and chemical handling systems
Petrochemical Process and fluid-handling systems
Heat-Related Equipment Selected piping and equipment operating at elevated temperatures
Industrial Engineering Fabrication and high-temperature industrial systems
Process Plants Corrosion-resistant process and utility piping

The suitability of 304H for a particular application should be evaluated against operating temperature, pressure, corrosion conditions, welding requirements and the applicable design code.

Industries Using Stainless Steel 304H Welded Pipe

Stainless Steel 304H Welded Pipes are used across industries requiring stainless steel piping with corrosion resistance and performance at elevated temperatures. Selection of the grade, pipe schedule, dimensions and testing requirements depends on the specific operating conditions.

Industry Typical Use
Power Generation High-temperature process and utility piping
Petrochemical Process piping and elevated-temperature systems
Chemical Processing Corrosive fluid and process piping
Oil & Gas Selected process and high-temperature piping systems
Process Engineering Industrial process equipment and piping
Industrial Manufacturing Fabricated equipment and process systems
Heat & Energy Systems Selected elevated-temperature piping applications

Kamal Steels supplies Stainless Steel 304H Welded Pipes from India for domestic and international industrial requirements. Pipes can be supplied in different sizes, schedules, wall thicknesses, lengths, finishes, testing conditions and material documentation according to project requirements.

Frequently Asked Questions

Stainless Steel 304H Welded Pipe is a high-carbon austenitic stainless steel pipe specifically designed for elevated temperature applications. It provides excellent oxidation resistance, improved creep strength and reliable performance in high-pressure and high-temperature environments.

The main difference is the carbon content. Stainless Steel 304H contains a higher carbon level than standard 304, which enhances high-temperature strength, creep resistance and durability in continuous heat service.

SS 304H Welded Pipes are manufactured according to ASTM A312, ASTM A358, ASTM A778, ASME SA312, ASME B36.19M and ASME B36.10M standards to ensure superior quality and dimensional accuracy.

Stainless Steel 304H Welded Pipes are available from 1/8" NB to 24" NB in schedules including SCH 5S, SCH 10S, SCH 40S, SCH 80S, SCH 160, XS, and XXS. Custom sizes and lengths are also available.

These pipes offer excellent oxidation resistance, superior high-temperature strength, enhanced creep resistance, good weldability, excellent mechanical properties and long service life in demanding industrial environments.

SS 304H Welded Pipes are widely used in boilers, heat exchangers, power plants, petrochemical industries, refineries, pressure vessels, chemical processing plants and other high-temperature process piping systems.

Each pipe undergoes Hydrostatic Testing, PMI (Positive Material Identification), Radiographic Testing, Eddy Current Testing, Flattening Test, Visual Inspection and Dimensional Inspection to ensure compliance with international standards.

Yes. Stainless Steel 304H Welded Pipes are supplied with EN 10204 3.1 Mill Test Certificates (MTC). Third-party inspection certificates are also available upon customer request.

Yes. We supply customized outside diameters, wall thicknesses, schedules, lengths, end preparations and surface finishes according to project specifications.

Kamal Steels is a trusted manufacturer, supplier, stockist, and exporter of Stainless Steel 304H Welded Pipes. We offer premium quality products, certified raw materials, competitive pricing, strict quality control, fast delivery, complete documentation and reliable worldwide export services.