The commonly used formula for estimating the theoretical weight of a solid round bar is:
Weight (kg/m) = 0.00623 × Diameter × Diameter
This coefficient (0.00623) is derived from the material density and the cross-sectional area of the bar. Below is a detailed explanation of the origin and use of this value.
The basic theoretical weight formula is:
Weight (kg/m) = Cross-sectional Area × Density = (π / 4 × d²) × ρ
Make sure all units are consistent — area in mm², density converted to kg/mm³.
The density of 304 stainless steel is approximately:
ρ = 7.93 g/cm³ = 7930 kg/m³
Substituting into the formula:
Weight (kg/m) = (π / 4) × d² × (7930 / 1,000,000) ≈ 0.006217 × d²
Rounded for engineering use: 0.00623 × d²
The theoretical weight per meter of a solid round bar made of 904L stainless steel can be calculated using the following standard formula:
Weight (kg/m) = (π / 4) × d² × ρ
Where:
ρ = 8.00 g/cm³ = 8000 kg/m³ = 8.0 × 10−6 kg/mm³
Weight (kg/m) = (π / 4) × d² × 8.0 × 10−6 × 1000
= 0.006283 × d²
Weight (kg/m) = 0.00628 × d²
(d is the diameter in mm)
For a 904L round bar with diameter 50mm:
Weight = 0.00628 × 50² = 0.00628 × 2500 = 15.70 kg/m
| Material | Density (g/cm³) | Coefficient (kg/m) |
|---|---|---|
| 904L Stainless Steel | 8.00 | 0.00628 |
| 304 / 316 Stainless Steel | 7.93 | 0.00623 |
| Carbon Steel | 7.85 | 0.00617 |
| Copper | 8.96 | 0.00704 |
The coefficient 0.00623 provides a quick and reliable way to calculate the theoretical weight of stainless steel round bars. For other materials, adjust the coefficient according to density.
If you need exact weights, cutting tolerance, or MTC-certified stainless steel bars, please feel free to contact Saky Steel.