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I. Theoretical Weight Calculation Formulas for Common Metal Materials
The theoretical weight calculation formulas for common metal materials are shown in Table 1 below.
Table 1 Theoretical Weight Calculation Formulas for Common Metal Materials
| No. | Category | Theoretical Weight m/(kg/m) |
| 1 | Round Steel, Steel Wire Rods, Steel Wire | m=0.00617×Diameter2 |
| 2 | Square Steel | m=0.00785×Side Length2 |
| 3 | Hexagonal Steel | m=0.0068×Distance Across Flats2 |
| 4 | Octagonal Steel | m=0.0065×Distance Across Flats2 |
| 5 | Equal Angle Steel | m=0.00785×Thickness×(2×Width-Thickness) |
| 6 | Unequal Angle Steel | m=0.00785×Thickness×(Long Side Width+Short Side Width-Thickness) |
| 7 | I-beam | m=0.00785×Web Thickness×[Height+f×(Flange Width-Web Thickness)] |
| 8 | Channel Steel | m=0.00785×Web Thickness×[Height+e×(Flange Width-Web Thickness)] |
| 9 | Flat Steel, Steel Plate, Steel Strip ① | m=0.00785×Width×Thickness |
| 10 | Steel Pipe | m=0.02466×Wall Thickness×(Outer Diameter-Wall Thickness) |
| 11 | Pure Copper Rod | m=0.00698×diameter2 |
| 12 | Hexagonal pure copper rod | m=0.0077×opposite side distance2 |
| 13 | Pure copper plate ① | m=8.89×thickness |
| 14 | Pure copper tube | m=0.02794×wall thickness×(outer diameter-wall thickness) |
| 15 | Brass rod | m=0.00668×diameter2 |
| 16 | Hexagonal brass rod | m=0.00736×opposite side distance2 |
| 17 | Brass plate ① | m=8.5×thickness |
| 18 | Brass tube | m=0.0267×wall thickness×(outer diameter-wall thickness) |
| 19 | Aluminum rod | m=0.0022×diameter2 |
| 20 | Aluminum plate ① | m=2.71×thickness |
| 21 | Aluminum tube | m=0.008478×wall thickness×(outer diameter-wall thickness) |
| 22 | Lead plate ① | m=11.37×thickness |
| 23 | Lead tube | m=0.0355×wall thickness×(outer diameter-wall thickness) |
Note:
1. For I-beams with the same waist height, if there are several different leg widths and waist thicknesses, add a, b, c to the right of the model to distinguish, such as 32a, 32b, 32c, etc. For channel steel with the same waist height, if there are several different leg widths and waist thicknesses, also add a, b, c to the right of the model to distinguish.
2. f value: The general model and those with an a are 3.34, those with a b are 2.65, and those with a c are 2.26.
3. e value: The general model and those with an a are 3.26, those with a b are 2.44, and those with a c are 2.24.
4. All length units are in mm.
① The unit of theoretical weight m is kg/m².
II. Calculation Formula for Theoretical Weight of Steel
See Table 2 below
Table 2 Calculation Formula for Theoretical Weight of Steel
| Name | Unit | Calculation Formula | Calculation Example |
| Round Steel Bar | kg/m | W=0.006165d2 In the formula, d is the diameter (mm) | For a round steel with a diameter of 80mm, calculate the weight per meter Mass per meter = 0.006165×80²kg = 39.46kg |
| Rebar | kg/m | W=0.00617d2 In the formula, d is the cross-sectional diameter (mm) | For rebar with a cross-sectional diameter of 12mm, calculate the weight per meter Mass per meter=0.00617×12²kg=0.89kg |
| Square Steel | kg/m | W=0.00785d2 In the formula, d is the width of the side (mm) | For square steel with a side width of 30mm, calculate the weight per meter Mass per meter=0.00785×30²kg=7.07kg |
| Flat Steel | kg/m | W=0.00785db In the formula, d is the width of the side (mm); b is the thickness (mm) | For flat steel with a side width of 40mm and thickness of 5mm, calculate the weight per meter Mass per meter=0.00785×40×5kg=1.57kg |
| Hexagonal Steel | kg/m | W=0.006798d2 In the formula, d is the distance between opposite sides (mm) | For hexagonal steel with an opposite side distance of 50mm, calculate the weight per meter Mass per meter=0.006798×50²kg=17kg |
| Octagonal Steel | kg/m | W=0.0065d2 In the formula, d is the distance between opposite sides (mm) | For octagonal steel with an opposite side distance of 80mm, calculate the weight per meter Mass per meter=0.0065×80²kg=41.60kg |
| Equal Angle Steel | kg/m | W=0.00785×[d(2b-d)+0.215(R2-2r2)] In the formula, b is the width of the side (mm); d is the thickness of the side (mm); R is the inner arc radius (mm); r is the end arc radius (mm) | To calculate the weight per meter of 4mm×20mm equal angle steel, find from GB/T 706—2008 that the R of 4mm×20mm equal angle steel is 3.5mm, and r is 1.2mm Mass per meter=0.00785×[4(2×20-4)+0.215(3.5²-2×1.2²)]kg=1.15kg |
| Unequal Angle Steel | kg/m | W=0.00785×[d(B+b-d)+0.215(R2-2r2)] In the formula, B is the width of the long side (mm); b is the width of the short side (mm); d is the thickness of the side (mm); R is the inner arc radius (mm); r is the end arc radius (mm) | Request the mass per meter for unequal angle steel of 30mm×20mm×4mm. From GB/T 706—2008, the R of 30mm×20mm×4mm unequal angle steel is found to be 3.5mm, and r is 1.2mm Mass per meter=0.00785×[4(30+20-4)+0.215(3.5²-2×1.2²)]kg=1.46kg |
| Channel steel | kg/m | W=0.00785×[hd+2t(b-d)+0.349(R2-r2)] In the formula, h is height (mm); b is leg length (mm); d is waist thickness (mm); t is average leg thickness (mm); R is inner arc radius (mm); r is end arc radius (mm) | Request the mass per meter for 80mm×43mm×5mm channel steel. From GB/T 706—2008, it is found that the t of this channel steel is 8mm, R is 8mm, and r is 4mm Mass per meter=0.00785×[80×5+2×8(43-5)+0.349(8²-4²)]kg=8.04kg |
| I-beam | kg/m | W=0.00785×[hd+2t(b-d)+0.8584(R2-r2)] In the formula, h is height (mm); b is leg length (mm); d is waist thickness (mm); t is average leg thickness (mm); R is inner arc radius (mm); r is end arc radius (mm) | For 250mm×118mm×10mm The mass per meter for I-beam. From GB/T706—2008, it is found that the t of this I-beam is 13mm, R is 10mm, and r is 5mm Mass per meter=0.00785×[250×10+2×13×(118-10)+0.8584(10²-5²)]kg=42.2kg |
| Steel plate | kg/m2 | W=7.85b In the formula, b is thickness (mm) | For a steel plate with a thickness of 6mm, request the mass per square meter Mass per square meter = 7.85×6kg =47.1kg |
| Steel pipe (including seamless and welded steel pipes) | kg/m | W=0.02466S(D-S) In the formula, D is outer diameter (mm); S is wall thickness (mm) | For a seamless steel pipe with an outer diameter of 60mm and a wall thickness of 4mm, request the mass per meter Mass per meter=0.02466×4×(60-4)kg=5.52kg |
Note: The theoretical mass calculated using the formula may differ from the actual mass, with a general error margin of about 0.2% to 0.7%, and can only be used as a reference for estimation.
III. Calculation formulas for the theoretical mass of non-ferrous metal materials
See Table 3 below
Table 3 Calculation formulas for the theoretical mass of non-ferrous metal materials
| Name | Unit of mass | Calculation formula | Calculation example |
| Pure copper rod | kg/m | W=0.00698×d2 In the formula, d is diameter (mm) | For a pure copper rod with a diameter of 100mm, the mass per meter = 0.00698×100²kg=69.8kg |
| Hexagonal pure copper rod | W=0.0077×d2 In the formula, d is distance between opposite sides (mm) | For a hexagonal pure copper rod with a distance between opposite sides of 10mm, the mass per meter Mass=0.0077×10²kg=0.77kg | |
| Pure copper plate | W=8.89×b In the formula, b is thickness (mm) | 5mm thick pure copper plate, mass per square meter = 8.89×5kg=44.45kg | |
| Pure copper tube | W=0.02794×S(D-S) In the formula, D is the outer diameter (mm); S is the wall thickness (mm) | Pure copper tube with an outer diameter of 60mm, thickness of 4mm, per Mass per meter=0.02794×4(60-4)kg=6.26kg | |
| Brass rod | W=0.00668×d2 In the formula, d is the diameter (mm) | Brass rod with a diameter of 100mm, mass per meter = 0.00668×100²kg=66.8kg | |
| Hexagonal brass rod | W=0.00736×d2 In the formula, d is the distance between opposite sides (mm) | Hexagonal brass rod with a distance between opposite sides of 10mm, per Mass per meter=0.00736×10²kg=0.736kg | |
| Brass plate | W=8.5×b In the formula, b is the thickness (mm) | Brass plate with a thickness of 5mm, mass per square meter Mass=8.5×5kg=42.5kg | |
| Brass tube | W=0.0267×S(D-S) In the formula, D is the outer diameter (mm); S is the wall thickness (mm) | Brass tube with an outer diameter of 60mm, thickness of 4mm, per meter Mass=0.0267×4(60-4)kg=5.98kg | |
| Aluminum rod | W=0.0022×d2 In the formula, d is the diameter (mm) | Aluminum rod with a diameter of 10mm, mass per meter = 0.0022×10²kg=0.22kg | |
| Aluminum plate | W=2.71×b In the formula, b is the thickness (mm) | Aluminum plate with a thickness of 10mm, mass per square meter Mass=2.71×10kg=27.1kg | |
| Aluminum tube | W=0.008796×S(D-S) In the formula, D is the outer diameter (mm); S is the wall thickness (mm) | Aluminum tube with an outer diameter of 30mm, wall thickness of 5mm, Mass per meter=0.008796×5(30-5)kg=1.1kg | |
| Aluminum plate | W=11.37×b In the formula, b is the thickness (mm) | 5mm thick lead plate, mass per square meter = 11.37×5kg=56.85kg | |
| Lead tube | W=0.355×S(D-S) In the formula, D is the outer diameter (mm); S is the wall thickness (mm) | Lead pipe with an external diameter of 60mm and a thickness of 4mm, per meter quality Mass=0.355×4(60-4)kg=7.95kg |
If you prefer not to calculate the metal weight manually using the formulas provided above, you can use an online metal weight calculator instead.
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