What formula is used to calculate hexagon bar weight?

The cross-section area of a regular hexagon is A = (√3 / 2) × AF² where AF is the across-flats distance. Weight is then: W = A × L × ρ, where L is the length and ρ is the material density.

What does "across-flats" mean?

Across-flats (AF) is the distance measured between two parallel, opposite flat faces of the hexagon. It is the standard way to specify hex bar size and is different from across-corners (vertex to vertex).

What is the weight of a hexagon bar?

A 24 mm across-flats carbon steel hex bar (density 7850 kg/m³) weighs about 3.92 kg per meter: Area = (√3 / 2) × 0.024² = 0.000499 m², then 0.000499 × 1 × 7850. Multiply by length for total weight.

What is the density of carbon steel?

Carbon steel (mild steel) has a density of approximately 7850 kg/m³ (0.284 lb/in³), which is the standard value used in most structural steel calculations.

Can I calculate weight for multiple bars?

Yes. Enter the quantity in the Quantity field and the calculator multiplies the single-bar weight by that number to give the total weight.

Does this work for metric and imperial units?

Yes. You can enter dimensions in millimeters, centimeters, inches, meters, or feet. Select the unit from the dropdown next to each input.

How accurate is this calculator?

Results represent theoretical weight based on nominal dimensions and standard densities. Actual bar weight may vary slightly due to manufacturing tolerances and surface condition.

Steel Hexagon Bar Weight Calculator

Name: Steel Hexagon Bar Weight Calculator
Availability: InStock
Author: Nham Vu

Enter the across-flats size, length, and material to instantly calculate the weight of a hexagon bar in kg or lbs.

Bar Dimensions

Across-Flats (AF) — flat face to flat face

Length

Material

Quantity (bars)

Formula Reference

A = (√3 / 2) × AF²
W = A × L × ρ

Where AF = across-flats (m), L = length (m), ρ = density (kg/m³), W = weight (kg).

Enter dimensions on the left and click Calculate.

Common Material Densities

Material	kg/m³	lb/in³
Carbon Steel	7850	0.284
Stainless 304	7930	0.286
Stainless 316	8000	0.289
Cast Iron	7200	0.260
Copper	8960	0.324
Brass	8500	0.307
Aluminum	2700	0.098
Titanium	4500	0.163

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Summary

Enter the across-flats size, length, and material to instantly calculate the weight of a hexagon bar in kg or lbs.

How it works

Enter the across-flats (AF) dimension — the distance between two parallel flat faces of the hex bar.
Select the unit for the across-flats value (mm, cm, or inches).
Enter the bar length and choose its unit (m, mm, ft, or in).
Select the material to apply the correct density.
Optionally enter a quantity for multiple bars.
The calculator applies Area = (√3 / 2) × AF², then Weight = Area × Length × Density and shows kg and lbs.

Use cases

Estimating material weight for structural and mechanical engineering projects.
Calculating freight and shipping weight for hex bar orders.
Bill of materials (BOM) preparation in manufacturing.
Comparing hex bar weights across different metals for product design.
Checking load limits on lifting and rigging equipment.
Cost estimation for machining and fabrication jobs.

Frequently Asked Questions

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Last updated: 2026-05-23 · Reviewed by Nham Vu