304H Stainless Steel Seamless Hydraulic Tubes & Instrumentation Tubes

High-Carbon Grade • Elevated Temperature Strength • Precision Bore Finish

Manufacturers and suppliers of 304H Stainless Steel Seamless Hydraulic Tubes & Instrumentation Tubes, engineered for high-temperature, high-pressure, dimensional accuracy, and reliable performance in thermal, chemical, and industrial process environments.

ISO 9001:2015 • ISO 14001:2015 • ISO 45001:2018 • PED 2014/68/EU • EN 10204 3.1/3.2 Certified

304H Stainless Steel Seamless Hydraulic Tubes & Instrumentation Tubes

Our 304H Stainless Steel Seamless Hydraulic Tubes & Instrumentation Tubes are engineered for high-temperature and high-pressure service environments where enhanced creep strength, dimensional accuracy, and long-term reliability are critical. Manufactured from high-carbon AISI 304H / UNS S30409 stainless steel, these tubes provide improved strength retention at elevated temperatures compared to standard 304 grades, making them ideal for thermal, chemical, and industrial process systems.

The seamless, high-precision construction ensures uniform wall thickness and a smooth, clean internal bore, reducing pressure drop and ensuring consistent performance in hydraulic circuits, pneumatic systems, and sensitive instrumentation lines operating under thermal cycling and demanding service conditions.

Widely used in power generation, refineries, petrochemical plants, heat treatment facilities, and high-temperature fluid handling systems, our 304H stainless steel seamless tubes are manufactured and tested to international standards, delivering a durable, cost-effective, and performance-driven solution for precision piping and elevated-temperature applications.

304H Stainless Steel Seamless Hydraulic Tubes & Instrumentation Tubes

Comprehensive Reach

Our 304H Stainless Steel Seamless Hydraulic Tubes & Instrumentation Tubes are trusted across major industrial cities in India, including Mumbai, Chennai, Pune, Ahmedabad, and Hyderabad, supporting power generation, chemical processing, automation, and large-scale infrastructure and EPC projects.

In the Middle East, we supply the UAE, Saudi Arabia, Qatar, Kuwait, Oman, Bahrain, Jordan, Iraq, and Lebanon, where our 304H stainless steel tubes are relied upon for high-temperature process systems, refineries, oil & gas facilities, and precision instrumentation in demanding thermal and pressure service environments.

Europe, Africa, Americas & Asia-Pacific

Across Europe—including Germany, Italy, France, Spain, the United Kingdom, Turkey, and Eastern European markets—our tubes are valued for their strength retention at elevated temperatures and dimensional accuracy in manufacturing, petrochemical, and industrial process systems. In Africa, the Americas, and the Asia-Pacific region, our products support power plants, mining operations, marine systems, and large-scale industrial projects operating in corrosive and high-temperature environments.

Commitment to Quality

Wherever you operate—Doha, Dubai, London, Moscow, or New York—Seminox Pipes & Tubes delivers premium-quality 304H Stainless Steel Seamless Hydraulic Tubes & Instrumentation Tubes, manufactured and certified to international standards for traceability, durability, and long-term performance in high-temperature and precision service applications worldwide.

Key Features of 304H Stainless Steel Seamless Hydraulic Tubes & Instrumentation Tubes

High-Carbon 304H Grade for Elevated Temperatures

AISI 304H / UNS S30409 stainless steel is designed for improved creep strength and strength retention at elevated temperatures, making these tubes ideal for high-temperature hydraulic, thermal process, and instrumentation systems.

High-Precision Seamless Manufacturing

Cold drawn and hot finished seamless processes ensure uniform wall thickness, tight dimensional tolerances, and a smooth, clean internal bore for reliable performance in precision fluid handling and control line applications.

Excellent Oxidation & General Corrosion Resistance

Provides strong resistance to oxidation and scaling at elevated temperatures, as well as general corrosion in industrial and chemical processing environments, ensuring long-term service reliability.

Stable Performance Under Thermal Cycling

Engineered to maintain mechanical integrity and dimensional stability during repeated heating and cooling cycles, improving system safety and operational consistency in high-temperature and pressure service conditions.

Reliable Strength for Pressure & Process Systems

Designed to withstand moderate to high operating pressures while maintaining precision bore geometry, ensuring dependable service in hydraulic circuits, process piping, and sensitive instrumentation networks.

Wide Size Range & Project-Specific Fabrication

Available in a broad range of diameters, wall thicknesses, and custom cut lengths, with optional bending, polishing, and special surface finishes to meet EPC, refinery, power plant, and OEM project requirements.

Product Specification – 304H Stainless Steel Seamless Hydraulic & Instrumentation Tubes

Outside Diameter
6.35 mm to 114.30 mm (1/4” to 4.5”)
Wall Thickness
0.71 mm to 12.70 mm (0.028” to 0.500”)
Grade / Material
Austenitic Stainless Steel – High Carbon Grade
AISI 304H / UNS S30409
EN 1.4948 / X6CrNi18-10
Manufacturing Process
Seamless (Hot Finished / Cold Drawn) • Solution Annealed • Pickled / Bright Annealed
Standards & Specifications
ASTM A213 / A213M – Seamless Alloy & Stainless Steel Tubes (Boiler, Superheater, Heat Exchanger)
ASTM A269 – Stainless Steel Tubing (General Service & Instrumentation)
ASTM A511 / A106 (Where applicable)
ASME SA213 / SA269
EN 10216-5 (Seamless Precision Tubes)
NACE MR0175 / ISO 15156 (If required for sour service)
Customer Drawings & EPC / Project Specifications
Length
Standard: 6 meters • Random Lengths • Up to 30 meters
Custom cut lengths, coiling & bending as per Project / OEM Requirements
Surface Finish
Annealed & Pickled (AP), Bright Annealed (BA),
Polished (180 / 240 / 320 / 400 Grit), Electropolished
Mechanical Properties (Typical)
Yield Strength: ≥ 205 MPa
Tensile Strength: 515–750 MPa
Elongation: ≥ 40%
Applications
Hydraulic & Pneumatic Systems, Instrumentation & Control Lines,
Heat Exchangers & Thermal Process Equipment,
Power Plants & High-Temperature Piping,
Oil & Gas Utilities, Refineries & Petrochemical Units,
Pressure Systems, Process Skids & OEM Assemblies

Manufacturing, Testing & Quality Assurance – 304H Stainless Steel Tubes

Advanced Manufacturing

304H Stainless Steel Seamless Hydraulic & Instrumentation Tubes are manufactured using precision hot finished and cold drawn processes, followed by controlled solution annealing and surface conditioning. This ensures a stable austenitic microstructure, excellent high-temperature strength, uniform wall thickness, and superior dimensional accuracy for critical hydraulic, instrumentation, heat transfer, and high-pressure process applications.

Inspection & Testing

Each tube undergoes comprehensive quality control including Eddy Current Testing (ECT), Hydrostatic or Pneumatic Pressure Testing, Positive Material Identification (PMI), chemical composition analysis, mechanical and flattening tests, dimensional inspection, surface roughness measurement, and 100% visual examination. These procedures ensure full compliance with ASTM A213, ASTM A269, and ASME SA213 / SA269 standards for safety, reliability, and long-term performance in demanding operating environments.

Certifications & Compliance

Manufactured in accordance with ASTM A213 / A269, ASME SA213 / SA269, EN 10216-5, ISO 9001:2015, ISO 14001:2015, ISO 45001:2018, and PED 2014/68/EU directives. Tubes are supplied with EN 10204 3.1 / 3.2 Mill Test Certificates (MTC), ensuring complete traceability, regulatory acceptance, and suitability for EPC, OEM, power generation, oil & gas, refinery, and high-temperature process projects.

Typical Applications of 304H Stainless Steel Seamless Hydraulic & Instrumentation Tubes

Hydraulic & Pneumatic Control Line Systems
Instrumentation Tubing for Process Monitoring & Automation
High-Temperature Process & Utility Piping
Power Generation & Thermal Plant Systems
Refineries, Petrochemical & Chemical Processing Units
Heat Transfer Lines, Boilers & Superheater Systems
Oil & Gas Facilities, Skids & Equipment Hook-Ups
OEM Manufacturing & Precision Fabrication
High-Pressure & High-Temperature Industrial Environments

Need 304H Stainless Steel Seamless Hydraulic & Instrumentation Tubes for Your Project?

Partner with Seminox Pipes & Tubes for certified, project-ready 304H Stainless Steel Seamless Hydraulic & Instrumentation Tubes manufactured to ASTM A213 / ASTM A269 / ASME SA213 / EN 10216-5 standards and supplied with EN 10204 3.1 / 3.2 Mill Test Certificates (MTC). Trusted worldwide for power generation, oil & gas, refineries, chemical processing, OEM manufacturing, and high-temperature process systems requiring precision, strength, and long-term operational reliability.

Get in Touch

Phone Number

022 6659 5296
+91 9987403801
+918433943801

Email

domestic@seminoxpipes.com
export@seminoxpipes.com

Address

1219 / 1220, 12th Floor, Prasad Chambers, Girgaon, Mumbai- 400004

Business Hours

Monday — Friday 9am – 5pm
Saturday — 10am – 3pm
Sunday — Closed

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