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Choosing the right stainless steel pipe grade comes down to three questions: what will the pipe be exposed to, how will it be joined, and how hot will it get in service. Siddhgiri Overseas has manufactured stainless steel pipe in Mumbai since 1962, and supplies the full 200-series, 300-series, and H-series grade range — SS 202, 304, 304L, 316, 316L, 321, 310, and 347H — in both seamless and welded construction. This page is built to help you narrow that range down quickly: it lays out how the grades differ on cost, corrosion resistance, weldability, and temperature capability, and groups them by the environment they're meant for. Once you've identified the grade that fits your application, follow through to its dedicated page for full chemistry, mechanical properties, and size availability.
With eight grades on offer, most selection decisions come down to four practical questions rather than a full metallurgy review.
Cost and nickel content. Nickel is the single biggest cost driver in austenitic stainless steel. SS 202 substitutes manganese for a portion of the nickel found in SS 304, which brings the price down but limits its use to dry, indoor, non-corrosive conditions. If the application doesn't involve outdoor exposure or moisture, 202 is worth evaluating before defaulting to 304.
Corrosion environment. Standard grades like SS 304 handle general atmospheric and food-grade conditions well, but chlorides — from seawater, coastal air, de-icing salts, or many process chemicals — attack them through pitting and crevice corrosion. SS 316 and SS 316L add molybdenum specifically to resist this, which is why they're the default choice for marine and chemically aggressive service rather than 304.
Weldability and the "L" grades. Any austenitic grade can suffer weld decay — intergranular corrosion in the heat-affected zone caused by chromium carbide precipitation during welding. If a pipe will be heavily field-welded, the low-carbon "L" version of its grade (304L instead of 304, 316L instead of 316) is the safer specification, since capping carbon content prevents this precipitation. The L grades trade a small amount of strength for that protection.
Temperature. For sustained high-temperature service, standard and L grades aren't the right fit. SS 321 and SS 347H use titanium and niobium stabilization respectively to resist weld decay without going low-carbon, which lets them hold strength at elevated temperature. SS 310 goes further, with high chromium and nickel content built for continuous service at extreme temperatures where even 321 and 347H aren't sufficient.
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SS 202 Pipe |
Lower-nickel, higher-manganese austenitic grade (~17-19% Cr, 4-6% Ni, 7.5-10% Mn); budget alternative to 304 |
Dry indoor applications — furniture, interior railings, decorative trim |
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SS 304 Pipe |
Standard "18/8" austenitic grade (~18% Cr, 8% Ni); yield 205 MPa, tensile 515 MPa |
General-purpose use — food processing, architecture, general industry |
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SS 304L Pipe |
Low-carbon version of 304 (carbon capped at 0.03% vs 0.08%); yield 170 MPa, tensile 485 MPa |
Heavily field-welded parts where weld-decay resistance matters |
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SS 316 Pipe |
Adds 2-3% molybdenum over 304 for much better pitting and crevice corrosion resistance from chlorides |
Marine, coastal, and chemically aggressive environments |
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SS 316L Pipe |
Low-carbon version of 316 with the same molybdenum addition; yield 170 MPa, tensile 485 MPa |
Heavy welding in marine or chemical service |
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SS 321 Pipe |
Titanium-stabilized grade; titanium binds with carbon so weld decay resistance holds without low-carbon content; yield 205 MPa, tensile 515 MPa |
Exhaust and thermal applications from 427°C to 816°C |
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SS 310 Pipe |
High-chromium, high-nickel grade (24-26% Cr, 19-22% Ni) for extreme temperature service |
Furnace components, kiln linings, radiant tubes up to about 1,150°C in dry air |
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SS 347H Pipe |
Niobium-stabilized, high-carbon-range grade (0.04-0.10% C); niobium carbides are more thermally stable than titanium and don't burn off during welding |
Refinery and power-generation piping — catalytic cracking units, boiler tubes — in the 400-815°C range |
General purpose. SS 304 Pipe covers the majority of standard applications — food-grade equipment, architectural work, general fabrication — where there's no unusual chloride exposure or high-temperature demand. SS 304L Pipe is the same grade adjusted for heavy welding.
Marine and chemical environments. SS 316 Pipe and SS 316L Pipe are built for chloride exposure — coastal structures, marine equipment, and process lines carrying aggressive chemicals. Choose the L version when the pipe will see significant field welding.
High temperature. SS 321 Pipe suits exhaust and thermal systems running between 427°C and 816°C. SS 347H Pipe is the fit for refinery and power-generation piping in the 400-815°C range where sustained strength and weld-seam stability both matter. SS 310 Pipe is reserved for the most extreme end — continuous service up to roughly 1,150°C in furnace, kiln, and radiant tube applications.
Budget and indoor use. SS 202 Pipe is the choice when cost matters most and the application stays dry and indoors — decorative and furniture-grade work rather than structural or outdoor use.
Siddhgiri Overseas is ISO certified for quality, occupational health & safety and environment management, and holds the import and export certification required to supply stainless steel pipe and tube to customers worldwide. Certificate copies are available on request for buyers who need them for their own compliance records.
SS 316 contains 2-3% molybdenum, which SS 304 does not. That addition gives SS 316 significantly better resistance to pitting and crevice corrosion from chlorides, making it the better choice for marine, coastal, or chemically aggressive conditions, while SS 304 remains suited to general-purpose use.
Choose an L grade when the pipe will be heavily field-welded. The lower carbon content (0.03% max) prevents chromium carbide precipitation in the heat-affected zone during welding, which avoids weld-decay corrosion. It comes with a modest reduction in yield and tensile strength compared to the standard grade.
It depends on the temperature and application. SS 321 and SS 347H are suited to sustained service in the 400-816°C range, with 347H specifically used in refinery and boiler piping. For continuous extreme heat up to around 1,150°C, such as furnace or kiln components, SS 310 is the appropriate grade.
SS 202 is generally the most budget-friendly grade in this range, since it replaces a portion of the nickel content used in SS 304 with manganese. It's suited to dry, indoor applications only and isn't recommended where moisture or outdoor exposure is involved.
Yes, it's common to specify different grades for different parts of the same project based on what each section is exposed to — for example, SS 304 for general piping runs and SS 316L for sections exposed to chlorides or heavy welding. Siddhgiri Overseas supplies across the full grade range so mixed specifications can be sourced together.
The "H" denotes a controlled higher-carbon range (0.04-0.10%), which helps the grade retain strength during sustained high-temperature service. Like SS 321, it resists weld decay through stabilization — SS 321 uses titanium, while SS 347H uses niobium, whose carbides are more thermally stable and don't burn off during welding, making 347H suited to demanding refinery and power-generation piping.
Yes. Siddhgiri Overseas has manufactured stainless steel pipe in Mumbai since 1962 and supplies this full 200-series, 300-series, and H-series grade range in both seamless and welded construction, with Mill Test Certificates provided for traceability.
