If you operate within the metals industry, you’re undoubtedly aware of the multifaceted considerations involved in determining the weight of steel. Accurate knowledge of steel weight holds substantial significance in project planning and cost estimation. In this blog post, we delve into the various methodologies for computing steel weight.
The unit weight of any substance is a measure of mass or weight per unit volume. It’s typically quantified in different units like pounds per cubic foot, grams per cubic centimeter, kilograms per cubic centimeter, or kilograms per cubic meter.
The unit weight of materials exhibits variance, contingent on their composition and constituent properties. This metric characterizes the material’s heaviness or lightness.
Unit Weight of Steel
The unit weight of steel, often referred to as the weighted density of steel, represents the ratio of steel’s weight to its unit volume. This is conventionally expressed in kilograms per cubic meter (kg/m³). For instance, the unit weight of mild steel plate or rolled steel stands at approximately 7850 kg/m³, which equates to 7.85 g/cm³, 78.5 KN/m³, or 489.84 lb/ft³. Steel weight is typically communicated in kilograms, metric tonnes, and pounds.
How to Compute Steel Weight:
Weight = Density × Volume (volume = Area × Length)
As an illustration, consider a bar with a diameter of 10mm and a length of 1 meter:
Area of the circular bar = π/4 × 10² = 78.5mm²
Volume = Area × Length = 78.5 × 1000 (since 1 meter = 1000mm) = 78500 mm³
Unit Weight of the 10mm steel bar = (7850/1000 × 1000 × 1000) × 78500 = 0.616 kg/m (Note: 1 kg/m³ = 0.000000001 kg/mm³)
Formula for Calculating Steel Bar Weight:
The formula for determining the unit weight of steel bars is D²/162, where “D” represents the diameter of the steel bars, and 162 is a constant value.
To elucidate the derivation of the D²/162 formula:
Suppose we have a steel bar with a diameter “D” and length “L.”
Weight of Steel Bar (W) = Unit Weight of Steel Bar (γ) x Volume (V)
W = γ x V
W = πD²/4 x γ (V = πD²/4)
Given that the unit weight of steel is approximately 7850 kg/m³ (γ):
W = πD²/4 x 7850
Converting the steel diameter from millimeters to meters:
W = π/4 x (D²/1000²) x 7850
W = D²/162.28 kg/m
W = D²/162 kg/m
Unit Weight Of Steel | ||
Size | Kg/m | Kg/feet |
6 mm | 0.222 kg | 0.067 kg |
8 mm | 0.395 kg | 0.120kg |
10 mm | 0.617 kg | 0.188 kg |
12 mm | 0.89 kg | 0.270 kg |
16 mm | 1.58 kg | 0.480 kg |
20 mm | 2.47 kg | 0.751 kg |
25 mm | 3.86 kg | 1.174 kg |
32 mm | 6.32 kg | 1.925 kg |
Steel Plate and Sheet Weight:
The weight of sheet metal adheres to a straightforward formula: Weight (lbs) = length (in) x width (in) x thickness (in) x density (lb/in³). For example, for a 1/4″ thick steel plate measuring 6″ x 8″, the weight calculation would be: 6″ x 8″ x 0.25″ x 10.2 lb/in³ = 97.6 lbs.
Steel Beams and Structures Weight:
Determining the weight of steel beams and structures is more intricate due to various variables, including beam size and shape. Professionals typically employ a “handbook calculation” method, which accounts for all design-related parameters. This approach is commonly used in designing projects involving steel beams and structures, such as bridges.
Steel Bars and Shapes Weight:
To compute the weight of bars and shapes crafted from steel, utilize this formula: Weight (lbs) = length (ft) x width (ft) x thickness (ft) x density (lb/ft³). For instance, for a 4″ square bar stock measuring 8′ in length, the weight can be calculated as follows: 8′ x 4′ x 0.33′ ft³ x 490 lb/ft³ = 781 lbs.
Steel Pipes Weight:
The weight of a steel pipe hinges on factors like length, diameter, and wall thickness. For precise results, employ the Weight formula for Steel pipes: W = 0.02466 x D²L / 10202, where “W” is the weight in kilograms per meter (kg/m), “D” is the outside diameter in millimeters (mm), and “L” denotes the length in meters (m).
Conclusion:
Accurately ascertaining the mass of steel can pose challenges contingent on the type—plate, sheet metal, beams, structures, bars, or shapes. However, armed with these practical formulas, you’ll find it easier to determine the weight of your materials. Whether you’re engaged in small-scale sheet projects or large-scale endeavors involving bars and shapes, mastering the art of steel weight calculation can streamline your project planning process.
FAQs:
The unit weight or density of steel is approximately 7850 kg/m³.
The formula for weight calculation of steel bars is D²/162 kg/m, where “D” represents the diameter of the steel bars.
The weight of a 12mm steel bar is approximately 0.888 kg/m.
The weight of an 8mm steel plate can vary depending on dimensions and steel type. As a rough estimate, it weighs approximately 62.8 kg/m² or 12.86 lb/ft².
The formula to calculate the quantity of steel for a project relies on various factors such as structure type, design requirements, and engineering specifications. However, a commonly used formula is: Quantity of Steel = (Length of Steel Bar * Number of Bars * Weight of Steel per Unit Length).
