Fabrication & buying
Stainless Steel Theoretical Weight Formulas & Linear Weight Guide
Calculate theoretical weights for stainless steel sheets, coils, tubes and bars. Freight estimation, container loading and scale vs theoretical weight.
Stainless steel trade distinguishes actual scale weight from theoretical weight. Mastering standard formulas ensures accurate container payloads and transparent freight quoting.
Sheet & coil theoretical weight
The standard formula for stainless steel sheet and coil:
Weight (kg) = Length (m) × Width (m) × Thickness (mm) × Density (g/cm³)
For Grade 304 (density 7.93 g/cm³):
• Standard 4×8 ft sheet (1219 × 2438 mm): 1.0mm thickness is 23.57 kg (approx. 42.4 sheets/MT); 0.8mm ≈ 18.86 kg; 1.2mm ≈ 28.28 kg; 1.5mm ≈ 35.35 kg; 2.0mm ≈ 47.14 kg.
• Standard 1×2 m sheet (1000 × 2000 mm): 1.0mm is 15.86 kg (approx. 63.0 sheets/MT); 1.5mm ≈ 23.79 kg; 2.0mm ≈ 31.72 kg.
For Grade 316L, molybdenum content raises density to 7.98 g/cm³ (+0.6% weight).
Tubes & profiles linear weight
Formulas for tubular and profile sections:
• Round tube (kg/m) = (OD - Wall) × Wall × 0.02491 (304) or 0.02507 (316L). Examples: OD 25.4×1.0mm ≈ 0.61 kg/m; OD 38.1×1.2mm ≈ 1.10 kg/m; OD 50.8×1.5mm ≈ 1.84 kg/m.
• Square / rectangular tube (kg/m) = [(Perimeter / 3.1416) - Wall] × Wall × 0.02491. Examples: 38×38×1.2mm ≈ 1.40 kg/m (6m bundle length ≈ 8.4 kg/pc); 50×50×1.5mm ≈ 2.33 kg/m (6m ≈ 14.0 kg/pc).
• Round bar (kg/m) = Dia² (mm²) × 0.00623. Example: Dia 20mm ≈ 2.49 kg/m; Dia 50mm ≈ 15.58 kg/m.
• Flat bar (kg/m) = Width (mm) × Thickness (mm) × 0.00793.
Density by stainless grade
Alloy compositions affect nominal density:
• 304 / 304L (18Cr-8Ni): Density 7.93 g/cm³. Standard austenitic grade for architectural, food and commercial fabrication.
• 316L (16Cr-10Ni-2Mo): Density 7.98 g/cm³. Mo-alloyed for chloride pitting resistance within 5km of marine environments.
• 430 (16-18Cr): Density 7.75 g/cm³. Nickel-free ferritic grade with high thermal conductivity, magnetic, for appliances.
• 201 (High Mn): Density 7.93 g/cm³. Cost-effective indoor decorative selection.
Theoretical vs actual scale weight
In stainless steel transactions, settlement terms must be specified:
• Theoretical Weight: Calculated based on nominal dimensions and mathematical formulas. Typical for cut-to-length sheets and standard tubes.
• Actual Scale Weight: Certified weight from truck scale / weighbridge minus tare (core paper/steel ID ring). Master cold-rolled coils and heavy plates are settled by verified scale weight.
Always agree whether the quotation is based on theoretical or scale weight.
Seaworthy export container loading
Ocean freight journeys encounter harsh temperature shifts and humidity. Jinlaibao strictly executes seaworthy export packing:
• Container payloads: 20GP containers are optimal for heavy coils and sheets (payload 25-27 metric tons, length ≤5.8m); 40HQ is ideal for 6m tubes and large metal fabrications (payload 26-28 metric tons).
• Packaging standard: ISPM 15 heat-treated solid wood or steel skids + inner VCI anti-corrosion barrier paper + full PE shrink wrap + galvanized metal edge guards + high-tensile steel strapping with internal timber chocking and container tie-downs.
Enquiry checklist outline
For immediate and accurate quotation, provide:
1. Grade & Standard: e.g. AISI 304 Cold Rolled Sheet / ASTM A312 316L Pipe.
2. Thickness & Tolerance: e.g. 1.0mm actual thickness (or mill minus tolerance).
3. Dimensions: Width × Length (Sheet) or OD × Wall × Length (Tube).
4. Surface & Protection: 2B / BA / No.4 Hairline / 8K Mirror; PE blue film or Fiber Laser film.
5. Quantity & Trade Terms: Sheets / Pieces / Metric Tons; FOB Guangzhou/Shenzhen or CIF destination port.