304 Stainless Steel Sheet Thickness Specifications

304 stainless steel sheets are classified based on production processes (cold-rolled or hot-rolled), standards (national, American, etc.), and application scenarios. The following provides detailed information on thickness classifications and tolerances.

1. Thickness Classification and Common Specifications

1.1 By Production Process

Cold-Rolled Stainless Steel Sheets (Thin Sheets)

🔹Thickness Range: 0.3mm ~ 3.0mm (Nominal thickness, actual minimum can go down to 0.1mm, requires customization)

🔹Common Specifications (mm): 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 1.0, 1.2, 1.5, 2.0, 2.5, 3.0

🔹Characteristics: Smooth surface (e.g., 2B/BA mirror finish), high precision, uniform thickness, suitable for precision processing (e.g., kitchenware, decorative panels, electronic components).

Hot-Rolled Stainless Steel Sheets (Medium to Thick Sheets)

🔹Thickness Range: 3.0mm ~ 100mm+ (some can reach 200mm, requires special customization)

🔹Common Specifications (mm): 3, 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 25, 30, 40, 50, 60, 80, 100

🔹Characteristics: Rough surface (hot-rolled acid pickled surface, No.1), larger thickness tolerance, used for structural components, machinery manufacturing, container plates, etc.

1.2 By Standard System

Chinese Standard (GB/T 3280-2015 for Cold-Rolled / GB/T 4237-2015 for Hot-Rolled)

🔹Nominal Thickness Range: 0.1mm ~ 200mm, common thicknesses match those in the above classifications.

American Standard (ASTM A240)

🔹Thickness Units: Inches (1 inch = 25.4mm). Common specifications include:

🔹Thin Sheets: 0.012" (0.3mm) ~ 0.120" (3mm)

🔹Medium-Thick Sheets: 0.125" (3.175mm) ~ 4" (101.6mm)

Japanese Standard (JIS G4305/G4304)

🔹Similar to Chinese standards, some thicknesses are denoted by "gauge" numbers (e.g., 16 gauge ≈ 1.6mm).

2. 304 Stainless Steel Sheet Thickness Tolerance Standards

Nominal Thickness (mm)	Allowable Deviation (mm, ±)	Example
≤0.4	0.04	0.3mm sheet actual thickness: 0.26~0.34mm
0.4~0.6	0.05	0.5mm sheet actual thickness: 0.45~0.55mm
0.6~1.0	0.07	1.0mm sheet actual thickness: 0.93~1.07mm
1.0~1.5	0.09	1.2mm sheet actual thickness: 1.11~1.29mm
1.5~2.0	0.11	2.0mm sheet actual thickness: 1.89~2.11mm
2.0~3.0	0.13	3.0mm sheet actual thickness: 2.87~3.13mm

Note: Hot-rolled sheets have slightly larger tolerances (e.g., 3mm thick hot-rolled sheet tolerance ±0.15mm, 10mm thick ±0.3mm). Specific tolerances can be found in GB/T 4237 or the supplier's certificate.

Nominal Thickness vs. Actual Thickness:
The "nominal thickness" is the theoretical value, while the actual thickness must be within the tolerance range. For example, if the order specifies a 1.0mm thick sheet, a deviation of ±0.07mm is allowed.

3. 304 Stainless Steel Sheet Application

Thickness Range	Typical Applications
0.3 ~ 1.0mm	Kitchen utensils (pots, sinks), decorative panels, electronic housings, signage
1.0 ~ 3.0mm	Building curtain walls, vehicle interiors, equipment housings, pressure vessel linings
3.0 ~ 10mm	Mechanical components (flanges, brackets), bridge structures, storage tank plates
Above 10mm	Heavy-duty equipment bases, ship decks, nuclear power pressure vessels