What formula is used to calculate copper hexagon bar weight?

The formula is: Weight = (√3/2) × AF² × Length × Density. AF (across-flats) and length are converted to meters. The cross-section area of a regular hexagon expressed in terms of across-flats distance is (√3/2) × AF². Multiplying by length gives volume (m³), and multiplying by copper alloy density (kg/m³) gives weight in kilograms.

What is the across-flats (AF) dimension?

The across-flats (AF) dimension, also called the "width across flats" or "wrench size", is the distance between two parallel flat sides of a hexagonal bar. It is the standard measurement used on hex bolts, nuts, and hex stock. It differs from the across-corners dimension, which is AF × (2/√3) ≈ AF × 1.155.

What is the density of copper used in this calculator?

Pure copper (C101) density is 8960 kg/m³. Electrolytic tough pitch copper (C110) is also 8960 kg/m³. Tellurium copper (C145) is 8940 kg/m³. Free-machining brass (C360) is 8490 kg/m³. Naval brass (C464) is 8410 kg/m³. Bearing bronze (C932) is 8800 kg/m³. You can enter a custom density for other alloys.

Does this calculator support metric and imperial units?

Yes. The across-flats dimension can be entered in mm, cm, or inches. Bar length can be entered in meters, mm, feet, or inches. All values are converted to meters internally before the calculation.

How does hexagon bar weight compare to round bar of the same nominal size?

A hexagon bar is heavier than a round bar of the same nominal (AF) diameter. The hexagon cross-section area is (√3/2) × AF² ≈ 0.866 × AF², whereas the round bar area is (π/4) × D² ≈ 0.785 × D². So a hex bar weighs about 10% more than a round bar of the same nominal size.

Can I calculate the total weight for multiple bars?

Yes. Enter the number of bars in the Quantity field and the calculator will show both the per-bar weight and the total weight for the entire batch.

Copper Hexagon Bar Weight Calculator

Enter the across-flats size, bar length, and copper alloy to instantly calculate copper hexagon bar weight in kg and lbs.

Bar Dimensions

Across-Flats (AF)

Distance between two parallel flat sides (wrench size).

Bar Length

Copper Alloy

Quantity (bars)

Formula Reference

W = (√3/2) × AF² × L × ρ

Where AF = across-flats (m), L = bar length (m), ρ = alloy density (kg/m³), W = weight (kg). Cross-section area = (√3/2) × AF² ≈ 0.866 × AF².

Enter dimensions on the left and click Calculate.

Copper Alloy Densities

Alloy	Grade / Use	kg/m³	lb/in³
C101	Pure / Oxygen-Free	8960	0.3238
C110	Electrolytic Tough Pitch	8960	0.3238
C145	Tellurium / Free-Machining	8940	0.3230
C360	Free-Machining Brass	8490	0.3067
C464	Naval Brass	8410	0.3038
C932	Bearing Bronze	8800	0.3179

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Summary

Enter the across-flats size, bar length, and copper alloy to instantly calculate copper hexagon bar weight in kg and lbs.

How it works

Enter the across-flats (AF) dimension of the hexagon bar in millimeters, inches, or centimeters.
Enter the bar length in meters, millimeters, feet, or inches.
Select the copper alloy grade from the dropdown.
Optionally enter a quantity for multiple bars.
The calculator applies W = (√3/2) × AF² × L × ρ and shows weight in kg and lbs.
Click Copy to save the result to your clipboard.

Use cases

Estimating copper hexagon bar weight for machining and CNC turning stock.
Calculating freight and shipping weight for copper hex bar stock orders.
Comparing alloy weights to select the right copper grade for the application.
Preparing bill of materials (BOM) for bolt, nut, and fastener manufacturing.
Verifying load limits on lifting and material handling equipment.
Cost estimation for copper hex bar purchases priced by weight.
Material planning for valve bodies, fittings, and plumbing components.
Comparing hex bar vs. round bar weight for the same nominal size.

Frequently Asked Questions

Last updated: 2026-09-19 · Reviewed by Nham Vu