---

304 stainless steel plate is a flat-rolled strip of 18/8 austenitic stainless that is thicker than 3 mm and sold as plate rather than sheet. It is the grade most buyers reach for when they need corrosion resistance without paying for molybdenum, and it welds, cuts and forms well enough to suit tanks, cladding, frames and food equipment. We product 304 plate in thicknesses from 3 mm to 120 mm and widths up to 2000 mm, and we cut it to size before it leaves the mill.

This page covers what 304 plate is made of, how it performs, how we size and certify it, and where it gets used. If you are deciding between 304 and 316, our surface finish guide and the 304 vs 316 brewery tank write up on the equipment side explain the grade choice in plain terms.

304 belongs to the austenitic family, the group with the highest chromium and nickel content among the common stainless grades. Its nickname is 18/8, because the typical analysis runs about 18 percent chromium and 8 percent nickel. Those two elements are what give 304 its corrosion resistance and its ability to stay tough at low temperature.

Plate is the thick end of flat-rolled stainless. In ASTM terms, sheet is 3 mm and under, and plate is over 3 mm. That single line decides how the material is rolled and what tolerances it carries, which is why we treat the 304 stainless steel sheet and the plate as two products even though the alloy is the same.

Most 304 plate is hot rolled, annealed and pickled to a No.1 finish, then ground or polished if a cleaner face is needed. It is non magnetic in the annealed state, though cold work from cutting or forming can bring up a little attraction at the edges.

The chemistry below is the ASTM A240 window for 304. The numbers are percentage by weight, with iron making up the balance.

Element	304	304L
Chromium	18.0 – 20.0	18.0 – 20.0
Nickel	8.0 – 10.5	8.0 – 12.0
Carbon	0.08 max	0.030 max
Manganese	2.0 max	2.0 max
Silicon	0.75 max	0.75 max
Phosphorus	0.045 max	0.045 max
Sulfur	0.030 max	0.030 max

The one number that matters for fabrication is carbon. Standard 304 allows up to 0.08 percent, while 304L caps it at 0.030. The low carbon version was made for welding: when you weld a thick plate, carbon at the heat-affected zone can pull chromium out of the mix and leave the seam open to corrosion. That failure mode is called sensitization. Drop the carbon and the weld stays protected, so 304L is the safer call for tanks, pipes and anything that gets welded a lot.

For most of our 304 plate orders the buyer picks 304L by default once thickness goes past 6 mm or the job involves much welding. The price gap is small and the weld safety is not.

We list 304 plate against three fields: thickness, the common width and length, and the theoretical weight. Weight is the number buyers use to price a job, so we give it directly rather than a formula alone.

Thickness (mm)	Common size (mm)	Weight (kg/m2)	Approx. weight per plate (kg)
3	1500 x 3000	23.79	107.055
4	1500 x 3000	31.72	142.74
5	1500 x 3000	39.65	178.425
6	1500 x 3000	47.58	214.11
8	1500 x 3000	63.44	285.48
10	1500 x 3000	79.3	356.85
12	2000 x 6000	95.16	1141.92
16	2000 x 6000	126.88	1522.56
20	2000 x 6000	158.6	1903.2
25	2000 x 6000	198.25	2379
30	2000 x 6000	237.9	2854.8
40	2000 x 6000	317.2	3806.4

Stainless 304 density is 7.93 g/cm3. To get kg per square metre, multiply thickness in mm by 7.93. To get the weight of one plate, use thickness (mm) x width (m) x length (m) x 7.93. For odd sizes, thickness (mm) x width (mm) x length (mm) x 0.00000793 gives the same answer. We cut to your drawing, so the weight on the quote matches the piece you receive, not the full mill plate.

The table below is the ASTM A240 minimum for annealed 304 plate at room temperature. Values shift a little with thickness and heat, so treat them as the floor, not the exact number for your heat.

Property	304 / 304L value
Tensile strength	515 MPa min (304), 485 MPa min (304L)
Yield strength (0.2% offset)	205 MPa min
Elongation	40 percent min
Hardness	201 HB max
Density	7.93 g/cm3
Melting range	1400 – 1450 C
Corrosion	Good in atmospheric, food, mild chemical service

304 resists rust in air, water, food and most mild chemicals. What it does not like is chloride. Pool water, seawater spray, road salt and some process streams with chloride will pit it over time. For those jobs, 316 with its 2 to 3 percent molybdenum is the step up, and that is the same reason our marine grade stainless steel line exists. 304 is the right plate for the other 80 percent of indoor and light outdoor work.

Plate leaves the hot line with a No.1 finish: a rough, dark, pickled face that is fine for structure but not for looks. From there you can take it several ways.

• No.1: hot rolled, annealed and pickled. The default for tanks and frames.
• 2B: cold rolled and passivated. Smoother than No.1, used where the face shows a bit.
• No.4: brushed with a 150 to 240 grit belt. The hygiene finish for food and pharma.
• BA (2R): bright annealed, near mirror on the clean side. For decorative and sanitary use.
• HL: hairline, a longer finer grain for interiors.

We finish brushed stainless steel and mirror stock in the same plant, so a 304 plate and a 304 sheet from us carry the same grain and flatness. Any mechanical finish is passivated after work to rebuild the chromium layer, which matters most on the welded seams.

Buyers mix these up because the alloy is identical. The difference is thickness and how the mill makes it, and that changes price, tolerance and what you can do with it.

Point	304 sheet	304 plate
Thickness	0.3 – 3 mm	3 – 120 mm
Rolling	Cold rolled	Hot rolled
Tolerance	Tight	Wider
Edge	Sheared, clean	Torch or plasma cut
Typical use	Panels, liners, light fabrication	Tanks, structure, heavy parts
Cost driver	Finish and flatness	Weight and cut time

If your part is under 3 mm and the face needs to look good, you want 304 stainless steel sheet. If it is thick, carries load, or gets welded into a vessel, plate is the form. We cut both, so you can order the thin liner and the thick end plate from one PO and keep the paper trail in one file.

We make 304 plate to ASTM A240 / A240M, the specification that covers chromium and nickel alloy plate for pressure and general service. For the European market we supply to EN 10088-2, and for Japan we work to JIS G4304 (hot rolled) and G4305 (cold rolled). The finish and flatness rules sit in ASTM A480, which we follow on every coil we finish.

Every plate ships with an EN 10204 3.1 mill test certificate that lists the heat number, the chemistry and the mechanical results. For corrosion grades we add PMI (positive material identification) so the heat is confirmed before it leaves. Third-party inspection by SGS, BV or TPI is available on request. Our full ASTM A240 certified stainless steel page covers the cert and MTC process in more detail.

304 plate shows up wherever a flat, corrosion resistant part has to take load or contact food. The table lists the sectors we supply most.

Sector	Why 304 plate	Common form
Food and beverage	Clean, weldable, food safe	No.4 tanks and benches
Chemical (mild)	Resists many weak acids	No.1 vessels
Construction	Cladding, columns, trim	2B, HL
Pharmaceutical	Easy to clean and sterilize	No.4, BA
Architecture	Bright, durable facades	BA, HL
Transport	Light, rust free frames	No.1, 2B
Water treatment	Resists fresh water	No.1, No.4
Energy (non chloride)	Heat and pressure parts	No.1

For marine, coastal or high chloride duty, step up to 316 or duplex. We cover that move in our 316 stainless steel sheet page and the marine grade guide.

Send us these points and we can quote the same day:

• Grade and standard: 304 or 304L, to ASTM A240 (see our ASTM A240 certified plate)
• Thickness, width and length, or the drawing if cut to shape
• Finish: No.1, 2B, No.4, BA or HL
• Quantity and any edge or hole work
• Tolerance and any third-party inspection
• Destination port for shipping

We can supply 304 and 304L stainless steel sheets in common sizes, with thicknesses ranging from 3 mm to 120 mm. The MOQ lead time for standard sizes is approximately one week; for thicker plates or those with special surface treatments, the lead time is three to five weeks. Please contact us for specific delivery times.

We have supplied 304 stainless plate since 2011 from our Zhengzhou base, with ISO 9001, 14001 and 45001 and CE marking. Stock in 304 and 304L ships within a week; special thickness and finishes run three to five weeks including rolling and machining. Every order leaves with an MTC and PMI on corrosion grades, and we pack for long sea freight so the faces arrive clean. When you need the related forms, our stainless steel hub links to sheet, coil, pipe, bar and the rest of the range.

Send your size, grade and finish to our sales team and we will quote the same day.

Hot Tags: 304 ss plate, 304L stainless steel plate, ASTM A240 304 plate, 304 stainless steel plate weight, 304 plate vs 304 sheet, 304 stainless steel plate price