Stainless steel grades at a glance
- 200 series (201, 202): austenitic, low nickel with manganese. Lower cost, for indoor and dry use. Not magnetic when annealed.
- 300 series (304, 304L, 316, 316L, 321, 310S, 904L): austenitic chromium-nickel grades. 304 for general and food use, 316 / 316L with molybdenum for chlorides and chemicals, 321 and 310S for heat. Not magnetic when annealed.
- 400 series: ferritic (409, 430, 434) for exhausts, appliances and decorative work; martensitic (410, 416, 420, 440C) hardenable for shafts, pumps, valves, cutlery and bearings. Magnetic.
- Duplex (2205, super duplex): about half austenite and half ferrite. Twice the strength of 304 / 316 with strong chloride resistance. Magnetic.
- Precipitation hardening (17-4PH / SS 630): high strength after ageing, for shafts, valves and aerospace parts. Magnetic.
* Annealed austenitic grades are essentially non-magnetic; cold working can make them slightly magnetic. Confirm grade by the mill test certificate or PMI, not with a magnet.
Common questions
Which stainless steel grade is best?
There is no single best grade. SS 304 is the general-purpose choice for food, dairy, water and architecture. SS 316 / 316L adds molybdenum for chlorides, sea air and chemicals. SS 202 is a lower-nickel option for indoor, dry use. SS 410 and 420 are hardenable for shafts, valves and cutlery; SS 430 is a ferritic grade for decorative and appliance use. Duplex 2205 suits high-chloride, high-strength duty.
Is stainless steel 304 magnetic?
Annealed SS 304 is essentially non-magnetic, but cold working (bending, drawing, rolling) can make it slightly magnetic. The 400 series (410, 420, 430), 17-4PH and duplex grades are magnetic. A magnet test cannot confirm a grade; use the mill test certificate or a PMI test.
What is the difference between SS 202 and SS 304?
SS 304 has about 8–10.5% nickel; SS 202 replaces much of the nickel with manganese (about 4–6% Ni, 7.5–10% Mn). SS 202 costs less but resists corrosion less, so it suits indoor, dry applications; SS 304 is preferred for food contact, water and outdoor use.
What is the difference between SS 304 and SS 316?
SS 316 adds about 2–3% molybdenum and a little more nickel, which improves resistance to chlorides, salt and many chemicals. Choose 316 / 316L for marine, coastal, pharma and chemical service; 304 is enough for most food and general uses.
What do 18/8 and 18/10 mean?
They describe roughly 18% chromium with 8% or 10% nickel, the composition range of SS 304. They are not grade designations on their own; ask for the grade and standard on the certificate.
What is the HSN code for stainless steel?
It depends on the product: sheets, plates and coils 7219 (600 mm wide or more) or 7220 (narrower), bars and rods 7222, wire 7223, welded pipe 7306 40, seamless pipe 7304 41 / 7304 49 and flanges and fittings 7307 2. See the stainless steel HSN code list.
Need stainless steel?
Steel Impex India in Mumbai supplies stainless pipes, tubes, sheets, plates, coils, round bars, flanges and fittings in 200, 300 and 400 series, duplex and nickel alloys across India, with mill test certificates. Send your requirement ↗
