Brass Weight Calculator

Weight Calculator Thread Size Chart Tap Drill Chart Limits & Fits Insert Installation Alloy Density All tools

Brass, copper & aluminium bar weight calculator

Estimate the weight of round, hex, square or octagon bar stock by alloy — brass, copper or aluminium. Useful for costing raw material, freight and per-piece yield.

Shape

Alloy

Diameter (mm)

Length (mm)

Quantity (pieces)

—

grams / piece

—

kg / metre

—

kg total

Densities are nominal; actual mass varies with exact composition and tolerance. Round: π·(d/2)²·L. Hex: (√3/2)·AF²·L. Square: side²·L. Octagon: 2(√2−1)·AF²·L.

Reference: alloy densities per EN 12164 / EN 12165 nominal values. See materials & alloys library.

How the calculator works

Bar weight is cross-sectional area × length × density: round π·(d/2)²·L·ρ, hex (√3/2)·AF²·L·ρ, square side²·L·ρ, octagon 2(√2−1)·AF²·L·ρ ≈ 0.8284·AF²·L·ρ (AF = across flats). Densities are the nominal EN 12164/12165 values for each alloy — see the materials library for full datasheets.

Worked example

Ø20 mm CW614N round bar, 1 metre: area = π×(1 cm)² = 3.1416 cm² → 3.1416 × 100 cm × 8.50 g/cm³ ≈ 2670 g ≈ 2.67 kg/m. The same bar in lead-free CW724R (8.30) weighs 2.61 kg/m — a 2.4% difference that matters at tender volumes.

Why bar weight matters when buying turned parts

Brass is quoted against metal value: raw material is often 60–80% of a turned part's cost. Weight per piece × alloy rod price gives your material floor price; weight per metre tells you the yield per 3 m bar including cut-off and facing losses. We quote parts to your drawing with material, machining and finishing broken out on request.

More engineering tools

Thread Size Chart

Major, pitch and minor diameters for ISO metric, UNC, BSP (G) and NPT threads — with tap drill sizes.

Tap Drill Chart

Recommended tap-drill sizes for ISO metric, UNC, BSP (G) and NPT threads at ~75% engagement.

Limits & Fits

Type a size and a class or fit — H7, g6, H7/g6, H7/p6 — and get limit dimensions and deviations.

Insert Installation

Boss hole diameters, heat-set tip temperatures and seating-force guidance for brass threaded inserts.

Alloy Density

Nominal densities of 20 brass, copper and aluminium alloys — CW614N 8.50, CW617N 8.47, C36000 8.49.

All engineering tools →

The complete Brassland toolset on one page.

Frequently asked questions

How do you calculate the weight of a brass bar?

Weight = cross-sectional area × length × density. Round bar: π×(d/2)²×L×ρ. Hex bar: (√3/2)×AF²×L×ρ. Square: side²×L×ρ. Octagon: 2(√2−1)×AF²×L×ρ ≈ 0.8284×AF²×L×ρ. For CW614N brass use ρ = 8.50 g/cm³.

How much does a 20 mm brass rod weigh per metre?

A Ø20 mm round bar in CW614N (8.50 g/cm³) weighs about 2.67 kg per metre: area = π×1² = 3.1416 cm², × 100 cm × 8.50 g/cm³ ≈ 2670 g.

What is the formula for octagon bar weight?

Area of a regular octagon measured across flats (AF) is 2(√2−1)×AF² ≈ 0.8284×AF². Multiply by length and density: an AF 20 mm octagon in CW614N weighs ≈ 2.82 kg/m.

Which density should I use for brass?

Leaded machining brasses are 8.4–8.5 g/cm³ (CW614N 8.50, CW617N 8.47). Lead-free silicon brass CW724R is lighter at 8.30 g/cm³; copper C11000 is 8.90. Temper has no practical effect on density.

Does a hex bar weigh more or less than a round bar of the same size?

A hex bar measured across flats weighs about 10% more than a round bar of the same diameter: hex area (√3/2)·AF² ≈ 0.866·AF² versus round π/4·d² ≈ 0.785·d².