Metal Length Calculator - Brass, Copper, Aluminium & Steel
Calculate the length of machined parts in brass, copper, aluminium, steel and engineering plastics from weight, by shape, grade and quantity.
Material (g/cm³)
No of Shapes
Unit
Part Name (Optional)
DWG No (Optional)
Shape
Weight
Diameter
Is Hollow?
A metal weight calculator finds the weight of a part from its shape, dimensions and material density. Weight equals cross-sectional area multiplied by length multiplied by density. Enter the material, pick a shape, add the dimensions, and the tool returns the weight in kilograms, plus material cost if you enter a rate per kg.
How to Use the Metal Weight Calculator
Five inputs, and the tool does the rest.
- 1.Select the material. The calculator works from density in g/cm³. Pick the grade you are actually buying, brass at 8.47 and copper at 8.96 give different weights for the same part.
- 2.Choose your output unit. Switch between kilograms and the unit your buyer works in.
- 3.Enter part quantity and rate per kg. You get total batch weight, and an indicative material cost when a rate is entered.
- 4.Pick the shape and enter dimensions. For a round profile, enter diameter and length. Tick 'Is Hollow?' for tube and enter the bore.
- 5.Add more profiles for a stepped part. Build up a multi-diameter component profile by profile, and the calculator totals them.
Round Bar Weight Per Metre (kg), Quick Reference
Common bar diameters in the four materials we machine most. Figures are theoretical weight per metre for solid round bar.
| Diameter (mm) | Brass CW614N | Copper C11000 | Aluminium 6061-T6 | Stainless 304 |
|---|---|---|---|---|
| 6 | 0.24 | 0.25 | 0.08 | 0.22 |
| 8 | 0.43 | 0.45 | 0.14 | 0.40 |
| 10 | 0.67 | 0.70 | 0.21 | 0.62 |
| 12 | 0.96 | 1.01 | 0.31 | 0.90 |
| 16 | 1.70 | 1.80 | 0.54 | 1.59 |
| 20 | 2.66 | 2.81 | 0.85 | 2.49 |
| 25 | 4.16 | 4.40 | 1.33 | 3.89 |
| 30 | 5.99 | 6.33 | 1.91 | 5.61 |
| 32 | 6.81 | 7.21 | 2.17 | 6.38 |
| 40 | 10.64 | 11.26 | 3.39 | 9.97 |
| 50 | 16.63 | 17.59 | 5.30 | 15.57 |
| 63 | 26.40 | 27.93 | 8.42 | 24.72 |
| 75 | 37.42 | 39.58 | 11.93 | 35.03 |
| 100 | 66.52 | 70.37 | 21.21 | 62.28 |
Metal Density Chart (g/cm³ and kg/m³)
A weight calculation is only as good as the density behind it. These are the working densities for the materials Amarex machines. Where grade matters, brass and stainless especially, use the specific grade rather than a family average.
| Material / grade | Density (g/cm³) | Density (kg/m³) | Typical Amarex use |
|---|---|---|---|
| Brass CW614N / CuZn39Pb3 (free-machining) | 8.47 | 8,470 | Turned components, fittings, glands |
| Brass C36000 (free-cutting) | 8.49 | 8,490 | High-volume turned parts |
| Brass 70/30 - C26000 / CZ106 | 8.53 | 8,530 | Deep-drawn and formed parts |
| Copper C11000 (ETP) | 8.96 | 8,960 | Electrical and earthing components |
| Aluminium 6061-T6 | 2.70 | 2,700 | Machined aluminium components |
| Aluminium 6063 | 2.70 | 2,700 | Machined profiles |
| Stainless steel 303 | 7.90 | 7,900 | Free-machining stainless parts |
| Stainless steel 304 | 7.93 | 7,930 | General corrosion-resistant parts |
| Stainless steel 316 / 316L | 8.00 | 8,000 | Marine and instrumentation parts |
| Carbon / mild steel | 7.85 | 7,850 | Machined steel components |
| Phosphor bronze | 8.80 | 8,800 | Bushes and bearing components |
| Gunmetal LG2 | 8.83 | 8,830 | Cast and machined bushes, valve bodies |
| Aluminium bronze C63000 | 7.58 | 7,580 | Marine and high-load bushes |
| Titanium Grade 5 (Ti-6Al-4V) | 4.43 | 4,430 | Special-alloy machined parts |
| Inconel 625 | 8.44 | 8,440 | High-temperature machined parts |
| Monel 400 | 8.80 | 8,800 | Corrosion-resistant machined parts |
| Hastelloy C276 | 8.89 | 8,890 | Chemical-service machined parts |
| PTFE | 2.20 | 2,200 | Machined plastic components |
| POM / Delrin | 1.41 | 1,410 | Machined plastic components |
| Nylon (PA6) | 1.14 | 1,140 | Machined plastic components |
| PEEK | 1.30 | 1,300 | High-performance plastic parts |
| Beech / maple (seasoned) | 0.70 | 700 | Machined wood components |
| Zamak 3 | 6.60 | 6,600 | Zinc-alloy components |
Weight Formulas by Shape
Every metal weight calculation is cross-sectional area multiplied by length multiplied by density. Only the area term changes with shape. Below, ρ is density in g/cm³ and all dimensions are in millimetres, giving weight in kilograms.
| Shape | Formula (metric) | Inputs |
|---|---|---|
| Round bar / rod | W = 0.7854 × D² × L × ρ / 1,000,000 | D = diameter mm, L = length mm |
| Tube / pipe (per metre) | W = 3.1416 × (OD - WT) × WT × ρ / 1,000 | OD = outer dia mm, WT = wall mm |
| Square bar | W = A² × L × ρ / 1,000,000 | A = side mm, L = length mm |
| Hexagonal bar | W = 0.866 × AF² × L × ρ / 1,000,000 | AF = across flats mm |
| Flat bar / sheet / plate | W = L × W × T × ρ / 1,000,000 | all mm |
| Ring / washer | W = 0.7854 × (OD² - ID²) × T × ρ / 1,000,000 | OD, ID, T in mm |
Worked Example: Brass Round Bar
A 25 mm diameter bar of CW614N brass, one metre long:
W = 0.7854 × 25² × 1000 × 8.47 / 1,000,000 = 4.16 kg per metre.
The same bar in copper weighs 4.40 kg per metre, and in 6061-T6 aluminium 1.33 kg per metre. Material choice changes both freight cost and handling.
Worked Example: Copper Tube
A 25 mm outer diameter copper tube with a 3 mm wall:
W = 3.1416 × (25 - 3) × 3 × 8.96 / 1,000 = 1.86 kg per metre.
Why Component Weight Matters When You Order Machined Parts
Weight drives three numbers on a machining quotation, which is why buyers calculate it before raising an enquiry.
- Material cost. Raw material is quoted per kilogram, so bar weight sets the material line before a single operation is costed.
- Freight. Air and sea freight are charged on weight and volume. A part moved from brass to 6061-T6 aluminium can cut shipped weight by more than half.
- Material utilisation. Bar stock weight against finished part weight shows how much material is turned away. A heavy ratio is usually the case for a near-net casting or a forged blank rather than machining from solid.
Amarex quotes against your drawing and your calculated weight, across the processes and size ranges we run in-house at Jamnagar.
Materials We Machine
The densities above map onto what Amarex actually manufactures. Everything listed is machined in-house at our Jamnagar plant, with our Mumbai head office handling enquiries, documentation and export logistics.
- Brass and copper alloys. 70/30 and 67/33 brass, free-machining CW614N and C36000, and ETP copper for turned components, fittings and electrical parts.
- Aluminium alloys. Led by 6061-T6, the grade we use most, alongside 6063 for machined profiles.
- Steel alloys. Free-machining 303, 304 and 316/316L stainless plus carbon and alloy steels.
- Special alloys. Monel, Inconel, Hastelloy, titanium and duplex for corrosion-critical and high-temperature components.
- Engineering plastics. PTFE, POM/Delrin, nylon and PEEK machined to the same tolerances as our metal work.
Frequently Asked Questions
Got the weight? Get the quotation.
Send us your drawing and calculated weight, and our team will quote material, machining and export packing against it. Quality systems and inspection documentation are available on request.
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