Short answer: For metric flat products, theoretical weight in kilograms equals thickness in millimetres × width in millimetres × length in metres × density in g/cm³ ÷ 1000. Use the density for the actual grade and distinguish theoretical weight from scale weight.
This guide is written for stainless steel buyers, sourcing teams, engineers and product manufacturers. The purpose is not to declare one universal winner, but to turn a broad material question into a specification that a mill or service center can quote, process and inspect consistently.
Quick Comparison
| Option | Key point | Typical use or decision |
|---|---|---|
| 304 sheet, 1.0 × 1000 × 2000 mm | 1.0 × 1000 × 2.0 × 7.9 ÷ 1000 | 15.8 kg |
| 430 strip, 0.5 × 200 mm × 1000 m | 0.5 × 200 × 1000 × 7.7 ÷ 1000 | 770 kg |
| 316L sheet, 1.2 × 1219 × 2438 mm | 1.2 × 1219 × 2.438 × 8.0 ÷ 1000 | About 28.5 kg |
The table is a starting point. Actual performance depends on the governing standard, delivered condition, dimensions, surface finish, fabrication route and service environment. Commercial names should never replace a complete purchase specification.
What Buyers Should Evaluate
- Use actual measured dimensions when reconciling shipments.
- Confirm grade density; ferritic and austenitic grades differ.
- Allow for packaging, cores and pallets when planning freight.
For production orders, share the end use rather than requesting a grade or finish in isolation. A supplier can then review corrosion exposure, forming severity, welding, visual requirements and packing before material is cut. This early review is usually less expensive than correcting a rejected shipment or unstable production trial.
Common Purchasing Mistakes
- Using 7.85 g/cm³ for every stainless grade
- Mixing millimetres and metres in one formula
- Treating theoretical weight as the invoiced net scale weight
These mistakes are avoidable when drawings, approved samples, inspection methods and certificate requirements are agreed before production. For visual products, retain a signed master sample. For functional dimensions, define where and how measurements will be taken.
Recommended RFQ Wording
Ask the quotation to show unit basis, theoretical or actual weight, dimensional tolerances, coil core weight treatment and allowable quantity variation.
Also include order quantity, acceptable quantity variation, destination, required delivery date and whether partial shipments are allowed. If a requirement is critical, make it measurable and place it on the purchase order rather than only in an email conversation.
How Still Steel Supports the Project
Still Steel supplies stainless steel coil, strip and sheet and provides slitting, cut-to-length, brushing, polishing and protective-film services. We can compare available mill material with your drawing, prepare trial quantities and preserve heat-number traceability through service-center processing.
Send the grade, dimensions, annual volume and application to vip@still-steel.com, or discuss the requirement on WhatsApp.
Frequently Asked Questions
What density should I use for 304?
A practical value is about 7.9 g/cm³; use the supplier’s grade data for contractual calculations.
Why does actual weight differ from theory?
Actual thickness, width, length, density and scale measurement vary within allowable tolerances.
Does protective film count in stainless weight?
It should not be treated as stainless net weight, but commercial invoicing and weighing procedures must be agreed.
Technical References
Reference documents support general selection and fabrication principles. The final material decision must follow the applicable contract, standard, regulation and engineering review for the specific product.