How to choose stainless steel sheet: thickness, finish, grade
A sheet is chosen for the job by four parameters: thickness, finish, grade and format. For décor take AISI 304 mirror; for a sink, table or food line — 2B or BA; for load-bearing structures — hot-rolled sheet 4–10 mm.
A mistake in one parameter breaks either the cutting layout or the corrosion resistance.
What follows is a step-by-step breakdown: how to read thickness and tolerance, how cold-rolled and hot-rolled sheet differ, which finish to take for the job, where each grade works and how to calculate metal consumption. The GCX catalogue lists 20 sheet items: thicknesses 0.8–10 mm, formats 1250×2500 and 1500×3000, grades 201, 304, 316L and 430.
Thickness and tolerances
Thickness is the first parameter to go into the specification, and the first one to cause a dispute later. The nominal value in the order and the actual thickness of the sheet in the batch are not the same thing: rolled steel is made with a tolerance range, and the standard sets how far the actual thickness may differ from nominal.
Cold-rolled sheet is made thinner, hot-rolled thicker. In the GCX catalogue cold-rolled starts at 0.8 mm, hot-rolled at 4 mm. This boundary is no accident: thin rolled steel is produced by cold rolling with an even surface and stable thickness, while from 4 mm upwards the metal is more profitably rolled hot and then ground if necessary.
| Thickness, mm | Rolling | Catalogue format | HS code | Typical job |
|---|---|---|---|---|
| 0.8–1.0 | cold | 1250×2500 | 721934 | cladding, sinks, panels |
| 1.5–3.0 | cold | 1250×2500, 1500×3000 | 721933, 721932 | food equipment, housings |
| 4.0 | hot | 1500×3000 | 721923 | structures, tanks |
| 5.0–10.0 | hot | 1500×3000 | 721922 | tanks, flanges, load-bearing parts |
Cold-rolled and hot-rolled sheet
Cold-rolled sheet is produced by rolling at room temperature followed by annealing. Hence its properties: an even surface without scale, stable thickness across the whole area, good flatness, a neat edge. The 2B, BA, №4 and mirror finishes are exactly this cold-rolled base. Such sheet is taken for everything visible and precise: sinks, tables, housings, panels, decorative inserts, and also as a blank for subsequent polishing and laser cutting.
Hot-rolled sheet is rolled at high temperature. It is thicker, the surface after rolling is darker and covered with scale, which is removed by pickling or left for mechanical processing. The thickness tolerance is wider and flatness lower, but the metal is cheaper per kilogram and better suited to structural parts. It is taken for structures, tanks, flanges and support elements, where what matters is not the look but strength and thickness.
In practice the choice is simple: if the part is visible and thin — cold-rolled. If the part carries a load and the thickness is from 4 mm — hot-rolled. An overlap is possible: 3 mm can also be cold-rolled in the 1500×3000 format, and thick sheet is sometimes ground for a decorative job.
Why actual thickness differs from nominal
The reason is technology. In cold rolling the metal springs back, in hot rolling it cools unevenly, so the manufacturer cannot deliver absolutely uniform thickness across the whole sheet area. The standard sets the tolerance range and rolling accuracy: for sheet these are ГОСТ 5582, 7350 and 19903. One describes cold-rolled steel, the second thin-sheet products, the third general requirements for the sheet product range.
This leads to a practical rule: the specification states not just "2 mm sheet" but the grade, finish, thickness, standard and rolling accuracy. Thickness without a tolerance is the most common cause of a dispute at acceptance. One more point: thickness is measured not right at the edge but at some distance from it, otherwise the edge gives a distorted result. If the part is critical, a thickness requirement and a control method are added to the specification.
If thickness is critical for the project, take metal with a margin and calculate the batch weight from the actual thickness in the certificate rather than the nominal value. A difference of tenths of a millimetre over a large batch makes a noticeable difference in tonnage.
Finishes: 2B, BA, №4, mirror
Finish is the second most important parameter after grade: it determines appearance, processing cost and how the sheet must be cared for.
| Finish | How it is produced | Appearance | Where it is used |
|---|---|---|---|
| 2B | cold rolling, annealing | matte, even | base sheet, food equipment, blank for polishing |
| BA | bright annealing | light, smooth | sinks, façades, food lines |
| №4 | abrasive grinding | matte with a directional pattern | handrails, kitchens, décor |
| mirror | multi-stage polishing | reflective | display cases, façades, interiors |
| hot-rolled | hot rolling | dark, with scale | structures, thick sheet |
AISI 304 mirror
Mirror sheet in 304 is the most common decorative item. Polishing removes the micro-relief and the surface begins to reflect. It does not follow that the mirror becomes more resistant: shine adds no protection to chromium and molybdenum. Outdoors, by the sea and with wet cleaning, such sheet performs according to the properties of the grade, not its looks. For wet and aggressive environments the mirror is taken in 316L or the surface is covered with a protective compound.
The price of mirror stainless steel sheet is made up of the grade, thickness, format and batch volume: polishing is a separate operation, and the higher the reflection class, the more expensive it is. If you need to buy mirror stainless sheet for a specific cutting layout, the order states the grade, thickness, format and finish.
Brushed stainless steel sheet AISI 304 is the same cold-rolled base, brought with abrasive to a №4 finish. Grinding is cheaper than polishing and more practical in use: scratches on it are masked, and it washes just as easily.
How 2B differs from BA
Both finishes are cold-rolled and smooth. 2B after annealing and pickling looks matte, BA after bright annealing is lighter and cleaner. The difference is noticeable on a façade and in a sink. For subsequent polishing and grinding, 2B is usually taken: the required finish is easier and cheaper to obtain from it than from BA.
Finish for the job
2B is the working finish for food equipment and the base sheet for any subsequent processing. It gives no glare and easily withstands washing with non-abrasive products.
BA is a light finish for places where a neat look matters: façades, sinks, filling lines. It is sensitive to fingerprints and requires a soft cloth and non-abrasive products.
№4 is a brushed finish with a directional pattern. Scratches on it are masked, so it is taken for handrails, work tables and kitchen lines. It is wiped along the pattern, not across it.
Mirror is the most demanding option. Any scratch and fingerprint shows, and regular care with stainless steel polish is needed. Outdoors and in areas of active contact the mirror quickly loses its looks.
Hot-rolled is a technical finish for painting, mechanical processing or hidden work. It is not used in food or decorative areas.
The general care rule for all finishes: do not use chlorine-containing or abrasive products, do not leave wet streaks and do not rub with a steel brush, which leaves particles of ordinary steel and provokes corrosion.
Grade for the job
The grade determines the environment in which the sheet will not rust. The catalogue has four options: 201, 304, 316L and 430.
| Grade | ГОСТ analogue | Environment | Typical job |
|---|---|---|---|
| 201 | 12Х15Г9НД | dry, indoors | décor, furniture, economy panels |
| 304 | 08Х18Н10 | water, moisture, food environments | sinks, tables, equipment |
| 316L | 03Х17Н14М2 | chlorides, salt, chemicals | marine environment, brines, chemical equipment |
| 430 | 12Х17 | dry, non-aggressive | interior finishing, household appliances |
304 is a universal grade: 18% chromium gives a passive film, 8–10% nickel gives toughness and workability. It is enough for water, moisture, food environments and outdoor use without chlorides. 316L differs by molybdenum, which slows pitting corrosion, so it is taken by the sea, in brines and in chemicals. 201 is cheaper: part of the nickel in it is replaced by manganese, resistance is lower, but so is the price. 430 is a ferritic grade without nickel, it is magnetic and suitable only for dry conditions.
A magnet is a poor acceptance tool. Austenitic 304 and 316L are weakly magnetic after annealing, and after cold deformation they begin to attract a magnet more strongly. Ferritic 430 is always magnetic. The grade is confirmed by the batch certificate, not by a magnet.
Cutting layout and weight
Sheet weight is calculated by the formula: thickness (mm) × width (m) × length (m) × 7.9. The density of stainless steel is about 7.9 g/cm³.
| Thickness, mm | Format, mm | Sheet weight, kg |
|---|---|---|
| 1.0 | 1250×2500 | 24.7 |
| 2.0 | 1250×2500 | 49.4 |
| 3.0 | 1500×3000 | 106.7 |
| 4.0 | 1500×3000 | 142.2 |
| 10.0 | 1500×3000 | 355.5 |
Cutting layout and consumption
The 1250×2500 format is 3.125 m², the 1500×3000 format is 4.5 m². The required number of sheets is calculated not by the area of the product but by the cutting plan. First the parts are laid out on the sheet taking into account the edge, the cut and the grinding direction, then the number of parts per sheet is multiplied by the number of products.
Example: a part 400×800 mm. By area, nine such parts fit into a 1250×2500 sheet, but the layout decides otherwise: three parts in a row of 400 mm give 1200 mm and leave 50 mm, and along the 2500 mm length three parts of 800 mm fit with 100 mm left over. In the end nine parts really come out only with a neat layout without allowance for the cut. Even 5 mm for the cut on each side can remove one part from the layout.
The metal utilisation rate is the share of the sheet area that went into the part. The higher it is, the less waste and the lower the metal consumption per product. That is why the format is chosen for the cutting plan: 1250×2500 is more convenient for small parts and standard bending, 1500×3000 for large panels and fewer joints. The difference in waste between a convenient and a correct format often outweighs any difference in the price per kilogram.
Cut-to-size is ordered as a separate operation. A laser gives an accurate contour, plasma is cheaper on thick metal, waterjet does not heat the edge. For thin decorative sheet minimal heating matters, otherwise the edge will warp.
Common mistakes when ordering sheet
- Ordering a grade without a finish. "304 sheet 2 mm" does not describe the delivery: 2B, BA, №4 and mirror are different items with different processing costs.
- Specifying thickness without a tolerance and standard. A nominal value without rolling accuracy leaves room for a dispute at acceptance.
- Choosing a format without a cutting plan. A bigger sheet is not always more profitable: the metal utilisation rate decides.
- Forgetting the standard and the certificate. The specification must contain the grade, finish, thickness, standard and format, and the delivery must include a document for the batch.
- Taking a 201 mirror outdoors or into a sink. The shine will go quickly, and the corrosion resistance of the grade is lower.
- Calculating the sheet price without converting to the tonne. The buyer compares the price per sheet, while the market counts per tonne — without the batch weight the comparison is meaningless.
Job, thickness, finish, grade
| Job | Thickness, mm | Finish | Grade |
|---|---|---|---|
| Decorative panel indoors | 0.8–1.5 | mirror, №4 | 201, 304 |
| Sink, food table | 1.0–2.0 | 2B, BA | 304 |
| Display case, outdoor façade | 1.0–2.0 | mirror, №4 | 304, 316L by the sea |
| Equipment housing | 1.5–3.0 | 2B | 304 |
| Tank, vessel | 3.0–5.0 | 2B, hot-rolled | 304, 316L |
| Flange, load-bearing part | 4.0–10.0 | hot-rolled | 304 |
| Chemicals, brines | 2.0–3.0 | 2B | 316L |
| Household appliance finishing | 0.8–1.0 | 2B, №4 | 430 |
Frequently asked questions
How does mirror stainless steel sheet differ from brushed?
Brushed sheet (№4) is matte, with a directional pattern from the abrasive. Mirror sheet is polished to a reflective state. The former is more practical on handrails and work surfaces, the latter on display cases and façades, where the look matters.
What is AISI 304 brushed?
The same 304 sheet, brought with abrasive to a matte №4 finish. It gives no glare and fingerprints and scratches are less noticeable, so it is taken for kitchen lines, counters and decorative inserts.
Is there matte stainless steel sheet?
2B and №4 are called matte. 2B has an even grey tone without a pattern, №4 has a directional matte look. If the order simply says "matte", clarify which finish is needed: the appearance of the product and the processing cost depend on it. A photo of matte stainless steel sheet conveys it only approximately: 2B and №4 are almost indistinguishable in a picture, and the finish is confirmed by a sample.
Does the catalogue include perforated and embossed sheet?
Perforated stainless steel sheet and embossed stainless steel sheet are not part of the GCX base product range: the sheet catalogue is smooth rolled product 0.8–10 mm. Chequered stainless steel sheet with a lentil pattern is a common pattern produced by separate processing at a contractor. The price of embossed stainless steel sheet depends on the pattern, thickness and batch volume.
How to calculate the weight of a stainless steel sheet?
Multiply the thickness in millimetres by the width and length in metres and by the density 7.9. For a 2 mm 1250×2500 sheet this is 2 × 1.25 × 2.5 × 7.9 = 49.4 kg. The exact batch weight is taken from the certificate; the calculation gives a guide for logistics.
Which format to choose — 1250×2500 or 1500×3000?
It depends on the cutting plan and the equipment. 1250×2500 is more convenient for small parts, 1500×3000 for large panels and fewer joints. Calculate the waste for each option and take the one where it is lower.
Can a mirror sheet be made of 201?
201 can also be polished, but the corrosion resistance of the grade is lower and the shine goes faster. For an interior without moisture this is acceptable; for outdoors, a kitchen and a sink it is not: there you need 304 or 316L.
How does cold-rolled sheet differ from hot-rolled?
Cold-rolled comes in thicknesses of 0.8–3 mm: even surface, accurate thickness, 2B, BA, №4 and mirror finishes. Hot-rolled is from 4 mm: darker surface, wider tolerance, it goes into structures, tanks and load-bearing parts.
Choose sheet for the job
Browse the product range and place an order with the grade, thickness, format, finish and shipment week — these parameters carry over into the trade without renegotiation.