Stainless Steel 304H Pipes & Tubes

Stainless Steel 304H Pipe & Tube Manufacturer, Supplier & Exporter in India

Amardeep Steel Centre is an ISO 9001:2015 certified manufacturer, stockist and exporter of stainless steel 304H pipes and tubes, supplying ASTM A312 and ASME SA312 TP304H material to refineries, boiler plants, thermal power projects and pressure-vessel fabricators since 1982. SS 304H pipe is held ex-stock in Mumbai in seamless, ERW and EFW construction from 1/2 inch NB to 100 inch NB, in schedules from SCH20 through XXS, and is dispatched with full documentation to more than 40 countries.

Whether your purchase order describes the material as 304H stainless steel pipe, SS 304H pipe, stainless 304H pipe or stainless steel pipe 304H, the alloy, specification and test certification are identical. Beyond nominal pipe schedules we also stock 304H stainless steel tubing in precision and instrumentation sizes to ASTM A213 and ASTM A249, where the OD and wall-thickness tolerances are tighter than any pipe schedule allows.

Every consignment ships with an EN 10204 3.1 or 3.2 Mill Test Certificate and IBR Form III-D. Third party inspection by SGS, Bureau Veritas, TUV or Lloyd's is available on request. Request a quote with your size, schedule and quantity and our technical team will confirm price and availability the same working day.

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What Is Stainless Steel 304H Pipe? (What Does the “H” Mean?)

Stainless steel 304H pipe is the controlled high-carbon version of Grade 304 austenitic stainless steel, manufactured to ASTM A312 and ASME SA312 TP304H. Standard 304 caps carbon at 0.08 percent maximum, and low-carbon 304L caps it at 0.035 percent maximum; 304H instead holds carbon between 0.04 and 0.10 percent and must meet an ASTM No. 7 fine grain size requirement. The extra, controlled carbon raises the alloy's tensile and creep-rupture strength at elevated temperature, which is why ASME B31.3 and the ASME Boiler and Pressure Vessel Code specify 304H rather than 304 or 304L for continuous pressure-retaining service above 525°C (980°F), where 304 and 304L gradually lose strength through creep.

The same alloy is specified internationally under several equivalent designations: UNS S30409, Werkstoff 1.4948, JIS SUS304H and the Euronorm name X6CrNi18-10. All describe identical chemistry and the same underlying ASTM A312 TP304H product, rated for continuous service to roughly 816°C (1500°F). Our article on stainless steel 304 composition, uses and properties covers the base metallurgy in more depth.

SS 304H vs 304 vs 304L vs 316H vs 321H: Which Grade Do You Need?

For service above 525°C where the environment is also chloride bearing or corrosive, step up to 316H, which adds molybdenum on top of the same high-carbon strategy. Where a titanium-stabilised option is preferred for heavy-wall welded fabrication, 321H is the alternative route. For a side by side look at the base grades, see our comparison of 304 vs 316 stainless steel.

Stainless Steel 304H Pipe Specifications

304H Stainless Steel Pipe Size and Weight Chart

Weights are calculated for TP304H at a density of 8000 kg per cubic metre and are indicative for estimation purposes. Dimensions follow ASME B36.19M/B36.10M and are identical across the austenitic grades, so the schedule/weight relationship below applies equally to 304, 304L and 316 pipe of the same size.

For a size not shown, use our steel weight calculator or the full pipe dimension chart. The schedule system itself is explained in our guide to the difference between Schedule 40 and Schedule 80 pipe.

304H Stainless Steel Tubing Sizes

In addition to nominal pipe sizes, we supply 304H stainless steel tubing in precision, instrumentation and hydraulic sizes to ASTM A213 and ASTM A249, where the fractional inch outside diameter is the controlling dimension.

Related tube products: 304H stainless steel micro tubing, welded austenitic stainless steel tube to ASTM A249 and A269 and stainless steel instrumentation tubing.

Chemical Composition of Stainless Steel 304H Tubes & Pipes

Values per ASTM A312 and ASME SA312 TP304H. 304H additionally requires an ASTM No. 7 (or finer) grain size, verified to ASTM E112, which standard 304 and 304L do not.

Mechanical and Physical Properties of SS 304H Pipes & Tubes

For weight and volume calculations see our reference on the density of stainless steel.

Equivalent Grades of Stainless Steel 304H

Pressure Rating of SS 304H Seamless Pipe

Indicative values based on Barlow's formula at ambient temperature for ASTM A312 TP304H seamless pipe, using the same 137.9 MPa (20 ksi) allowable stress basis as TP304 and TP316 since all three share the 515 MPa minimum tensile / 205 MPa minimum yield strength at room temperature. Verify against ASME B31.3 or the applicable piping code before use in engineering design. These figures do not constitute a design specification.

Allowable Stress for SS 304H Pipe per ASME B31.3

304H shares ASME B31.3's base allowable-stress curve with standard TP304 up to roughly 800°F (427°C), since both share the same minimum tensile and yield strength. Above approximately 1000°F (538°C), fine-grain 304H material meeting the grain-size note in Table A-1 may qualify for a materially higher allowable stress than standard 304 because of its controlled carbide and grain-size chemistry, this is the specific advantage the “H” designation buys in creep-governed design. Confirm the exact high-temperature values against the current edition of ASME B31.3 Table A-1 with your piping engineer before finalising a design; figures above are indicative and do not constitute a design specification.

Why 304H Outperforms 304 and 304L Above 525°C

SS 304H's advantage over 304 and 304L is not corrosion resistance — all three share the same 18 to 20 percent chromium, 8 to 10.5 percent nickel base chemistry and near identical general corrosion performance. The difference is creep and stress-rupture strength at elevated temperature. The controlled 0.04 to 0.10 percent carbon range and mandatory ASTM No. 7 grain size give 304H measurably better long-term strength above roughly 525°C (980°F), where standard 304 is limited to lower allowable stresses by code and 304L, capped at 0.035 percent carbon, is not normally specified for sustained high-temperature pressure service at all.

Where the operating environment combines high temperature with chlorides or aggressive process chemicals, step up to 316H, which adds molybdenum to the same high-carbon strategy, or to 309H, 310H, 321H or 347H for even higher temperatures or where stabilisation against sensitisation is required.

Manufacturing Process of SS 304H Pipes

Seamless to ASTM A312 and ASME SA312

Produced by hot extrusion or rotary piercing from solid billet, followed by cold drawing and solution annealing at 1010 to 1120°C, with grain size verified to meet the ASTM No. 7 requirement. With no seam weld and uniform wall thickness, seamless 304H pipe is the choice for high pressure, high temperature and high cycle fatigue service.

ERW to ASTM A312 and ASME SA312

Strip is roll formed into a tube and seam welded by electric resistance, then the weld seam is heat treated so its strength and grain structure match the parent metal. ERW 304H pipe is the standard for general high-temperature process piping at lower cost than seamless.

EFW to ASTM A358 and ASME SA358

Electric fusion welded from plate or strip, this is the standard route for large diameter fabricated pipe from 6 inch to 100 inch in refinery and power plant applications. See our ASTM A358 and ASME B36.19M pipe range.

LSAW

Longitudinally submerged arc welded, used for heavy wall structural and high pressure large diameter applications where EFW is insufficient. All welded 304H pipe and tube is solution annealed and pickled before despatch.

Choosing between the two routes is covered in our guide to the difference between seamless and welded pipe.

Surface Finish Options for SS 304H Pipes & Tubes

Dimensional Tolerances for SS 304H Pipes & Tubes

Outside diameter tolerance

Dual Certified 304 / 304H Pipe

A single heat can often qualify as both UNS S30400 (304) and UNS S30409 (304H) simultaneously, provided its carbon content falls in the overlapping 0.04 to 0.08 percent band and it meets 304H's ASTM No. 7 grain-size requirement. Dual certified 304/304H pipe lets one heat serve both general-purpose and elevated-temperature pressure applications, which simplifies inventory on mixed-service packages. Amardeep supplies dual certified pipe on request, so confirm the requirement on your purchase order.

SS 304H Pipe Price per Kg in India

Stainless steel 304H pipe prices move with nickel input costs and the prevailing alloy surcharge, and vary further by size, schedule, manufacturing route, surface finish and order quantity. Because 304H carries no molybdenum, indicative pricing generally sits below the 316 family for equivalent sizes. The ranges below are indicative for standard schedules in trade quantities.

Get today's exact price for your size and we will quote against your specific grade, NPS, schedule and tonnage.

Ex Stock Availability

If your size is not listed we can manufacture to custom specification within two to four weeks. Check availability.

Quality Assurance, Testing and Documentation

Every batch of Amardeep SS 304H pipe and tube is supplied with:

• Mill Test Certificate to EN 10204 3.1 or 3.2
• IBR Test Certificate, Form III-D, for Indian Boiler Regulation compliance on IBR pipes and tubes
• Chemical and mechanical test reports covering tensile, yield, elongation and hardness
• Grain size verification to ASTM E112, confirming compliance with the ASTM No. 7 requirement specific to TP304H
• NDT reports covering ultrasonic, radiographic, eddy current and magnetic particle testing
• Positive Material Identification on request
• Hydrostatic and flattening test results
• Third party inspection by SGS, Bureau Veritas, TUV or Lloyd's on request

We are ISO 9001:2015 certified. View our quality certifications and testing capabilities.

Applications of Stainless Steel 304H Pipes & Tubes

• Oil refineries and petrochemical: high-temperature process piping, catalytic reformer and crude unit lines
• Power generation: boiler, superheater and reheater piping, heat exchanger tubes and boiler tubes
• Pressure vessels: ASME Section VIII vessels operating continuously above 525°C
• Chemical processing: high-temperature reactors, furnace and cracking-unit piping
• Heat exchangers and condensers: condenser tubes for hot process fluids
• Furnace, kiln and incinerator components: radiant tubes and structural supports in sustained high-heat service

Export and Packaging

Amardeep Steel Centre exports stainless steel 304H pipe to the UAE, Saudi Arabia, Qatar, Oman, USA, UK, Germany, Netherlands, Singapore, Malaysia, Vietnam, Indonesia and Australia on FOB, CIF and EXW terms. Pipes are bundled with steel strips, wrapped in waterproof covering and packed in wooden crates or seaworthy export packing as required. Each length is marked with NB, schedule, specification, grade, heat number and manufacturer's symbol for full traceability. 

Related Products

SS 304H Buttweld Fittings, SS 304H Forged Fittings, SS 304H Flanges, SS 304H Plates, Sheets & Coils

SS 304, SS 304L, SS 316, SS 316H, SS 309H, SS 310H, SS 321H, SS 347H, Stainless Steel Pipes & Tubes