How much will it weigh?
Rounds, squares, hex, flats, plates, tubes and MS pipes by schedule, square and rectangular pipes, angles, beams and channels, in any of our 27 materials. Add the result to your request and the concierge quotes it.
W = π × D² × L × ρ ÷ 4,000,000 · ρ = 7.85 g/cm³ · rounded to 0.1 kg. Theoretical weight; actual mill weight can vary by ±2–3%.
The formulas
- Round
- W = π × D² × L × ρ ÷ 4,000,000
- Square
- W = S² × L × ρ ÷ 1,000,000
- Hex
- W = 0.866025 × A/F² × L × ρ ÷ 1,000,000
- Flat
- W = T × W × L × ρ ÷ 1,000,000
- Plate / sheet
- W = T × W × L × ρ ÷ 1,000,000
- Tube / pipe
- W = π × (OD − WT) × WT × L × ρ ÷ 1,000,000 (with an inside diameter, WT = (OD − ID) ÷ 2)
- Square pipe
- W = 4 × (A − WT) × WT × L × ρ ÷ 1,000,000 (with an inside size, WT = (A − a) ÷ 2)
- Rectangular pipe
- W = (2(A + B) − 4·WT) × WT × L × ρ ÷ 1,000,000 (with inside sizes, WT = (A − a) ÷ 2 = (B − b) ÷ 2)
- Angle
- W = (A + B − T) × T × L × ρ ÷ 1,000,000
- Beam (ISMB)
- W = IS 808 kg/m × L ÷ 1,000
Dimensions in millimetres, density ρ in g/cm³, weight in kilograms. Beams and channels use IS 808 nominal kg/m.
Tubes and square or rectangular pipes can be entered by wall thickness or by inside size. MS pipe (SCH) takes the outside diameter and wall thickness from the pipe schedule (ASME B36.10M, SCH 10 to SCH 160, STD, XS, XXS): pick the nominal size and the schedule.
By material
| Material | g/cm³ |
|---|---|
| Mild / structural steel | 7.85 |
| Alloy & tool steel | 7.85 |
| High speed steel M2 | 8.16 |
| Stainless 304 / 316 | 8 |
| Stainless 202 | 7.8 |
| Stainless 410 / 420 | 7.75 |
| Stainless 431 | 7.7 |
| Stainless 17-4PH | 7.8 |
| Brass | 8.5 |
| Electrolytic copper | 8.96 |
| Gunmetal LG2 | 8.83 |
| Phosphor bronze PB1 | 8.8 |
| Aluminium bronze AB2 | 7.6 |
| Manganese bronze | 8.3 |
| Aluminium 6061 / 6063 | 2.7 |
| Aluminium 7075 | 2.81 |
| Aluminium 5083 | 2.66 |
| Grey cast iron | 7.2 |
| SG / ductile iron | 7.1 |
| Nylon 6 | 1.14 |
| Cast nylon (oil filled) | 1.15 |
| Delrin / acetal | 1.41 |
| PTFE (Teflon) | 2.2 |
| Polypropylene | 0.9 |
| UHMWPE | 0.93 |
| Bakelite (phenolic) | 1.36 |
| Acrylic (PMMA) | 1.19 |
How is the weight of a steel round bar calculated?
Weight (kg) = π × D² × L × density ÷ 4,000,000, with D and L in mm and density in g/cm³. For mild or alloy steel (7.85 g/cm³) a 25 mm round weighs 3.85 kg per metre.
What density do you use for stainless steel, brass and aluminium?
Stainless 304/316 8.00, stainless 410/420 7.75, brass 8.50, copper 8.96, gunmetal 8.83, phosphor bronze 8.80, aluminium 6061/6063 2.70 and grey cast iron 7.20 g/cm³.
Is the calculated weight what I will be invoiced?
No. It is the theoretical weight. Invoices use the actual weighed or mill weight, which can differ by ±2–3% because of rolling tolerances.