What formula is used to calculate glass 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 glass density (kg/m³) gives weight in kilograms.

What is the across-flats (AF) dimension?

The across-flats (AF) dimension, also called "width across flats," is the distance between two parallel flat sides of a hexagonal bar. It differs from the across-corners dimension, which is AF × (2/√3) ≈ AF × 1.155.

What glass densities does this calculator use?

Default is borosilicate glass at 2230 kg/m³. Soda-lime glass is 2500 kg/m³, fused silica is 2200 kg/m³, quartz glass is 2650 kg/m³, and lead crystal is 3100 kg/m³. A custom density field is provided for specialty glass types.

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 glass 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.

Glass Hexagon Bar Weight Calculator

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

Bar Dimensions

Across-Flats (AF)

Distance between two parallel flat sides (wrench size).

Bar Length

Glass Type

Quantity (bars)

Formula Reference

W = (√3/2) × AF² × L × ρ

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

Enter dimensions on the left and click Calculate.

Glass Type Densities

Glass Type	Common Use	kg/m³	lb/in³
Borosilicate	Lab / Pyrex	2230	0.0806
Soda-Lime	Float / Window	2500	0.0903
Fused Silica	High-Purity Optical	2200	0.0795
Quartz Glass	UV / Semiconductor	2650	0.0957
Lead Crystal	Optical / Decorative	3100	0.1120
Aluminosilicate	High-Temp / Gorilla	2530	0.0914

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Summary

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

How it works

Enter the across-flats (AF) dimension of the glass hexagon bar in millimeters, inches, or centimeters.
Enter the bar length in meters, millimeters, feet, or inches.
Select the glass type from the dropdown to apply the correct density.
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 glass hexagon bar weight for optical component fabrication.
Calculating freight and shipping weight for glass rod and bar orders.
Comparing glass type weights to optimize optical instrument design.
Preparing bill of materials for laboratory glassware manufacturing.
Verifying load limits when handling precision glass bar stock.
Cost estimation for glass hex bar purchases priced by weight.
Material planning for scientific instrument and lens grinding applications.
Comparing hex bar vs. round bar weight for the same nominal glass size.

Frequently Asked Questions

Last updated: 2026-09-20 · Reviewed by Nham Vu