Hex Bar Weight Calculator

What the hex bar weight calculator does

Hex bar is a solid six sided bar sold by its size across flats, the distance between two opposite flat faces. The hex bar weight calculator turns that size into a cross section area, multiplies by the length for the volume, and multiplies by the metal density for the weight. You get the total weight for your pieces, the hex bar weight per meter, the hex bar weight per foot, and the size across corners, which tells you the round stock a hex will fit inside.

Hex bar weight formula

A regular hexagon with size across flats A has an area of the square root of 3 divided by 2, times A squared. Multiply by the density for the weight per meter:

For steel at 7.85 g/cm³ this hex bar weight formula collapses to a handy shortcut, kg/m = 0.0068 × A², with A in millimeters. Multiply the weight per meter by the length in meters and by the piece count for the total.

Hex bar weight calculator example

Take a 20 mm steel hex bar, 1,000 mm long. The hex bar weight calculator works it out like this:

So one meter weighs 2.719 kg, which is 1.827 lb per foot, and the bar measures 23.09 mm across the corners. Switch the material to brass and the same bar comes out at 2.944 kg/m, because brass is denser than steel.

How to use the hex bar weight calculator

Choose the material, enter the size across flats in millimeters, the length of one piece in millimeters, and the number of pieces. Press Calculate and the hex bar weight calculator returns the total weight and the unit weights. For inch stock, multiply the inch size by 25.4 first, so a 1 inch hex goes in as 25.4 mm. Measure across flats with calipers on the flat faces, never across the corners.

Reading hex bar weight per meter and per foot

The hex bar weight per meter is the unit weight for that size and metal, and the total is that figure times the length and quantity. Mill catalogs list steel hex in kg/m or lb/ft, so the two unit weights let you check a quote either way. Weight grows with the square of the size: a 30 mm hex weighs 6.118 kg/m, more than twice a 20 mm bar. The across corners figure, 1.1547 times the flats size, is the smallest round bar that a hex of that size can be machined from.

When to use a hexagon bar weight calculator

• Pricing hex stock sold by the kilogram or pound
• Checking a delivery note against the steel hex bar weight
• Planning crane, rack, and shelf loads for bar storage
• Estimating shipping weight for nut, fitting, and bolt blanks
• Comparing brass hex bar weight with steel before you choose a material

Common hex bar weight calculator mistakes

• Measuring across corners. The corner size is 15.5% larger and overstates the weight by about a third.
• Mixing units. Enter the size and length in millimeters; convert inch stock by multiplying by 25.4.
• Wrong metal. Brass and stainless weigh more than carbon steel; aluminum weighs about a third.
• Forgetting the quantity. The total covers all pieces only when you enter the count.

Tips for hex bar weight takeoffs

• Add 3 to 5% for saw kerf and end trim when you price a cut list.
• Use the across corners size to pick round stock if you machine your own hex.
• Quote stock lengths, usually 3 m, 6 m, or 12 ft, so the supplier can match the weight.

Related metal weight tools

Hex bar sits next to the other solid bar shapes. For a round section, the round bar weight calculator gives weight from diameter, and the square bar weight calculator covers solid square stock. Use this hex bar weight calculator whenever the bar has six flat faces.

Hexagon bar weight formula from first principles

A regular hexagon splits into six equal triangles that meet at the center. With a size across flats of A, each triangle has a base of A divided by the square root of 3 and a height of A divided by 2, so the six of them add up to the square root of 3 divided by 2 times A squared, or 0.866 A². That is the area the hexagon bar weight formula uses. Multiply by a length of one meter and you have the volume of a one meter piece in mm² times meters; multiply by the density in g/cm³ and divide by 1,000 and the answer lands in kilograms per meter. The same steps give the round bar shortcut of d² ÷ 162, which explains why a hex of size A always weighs 0.866 divided by 0.7854, or about 1.10 times, a round bar of diameter A. A useful check for any hex steel weight calculator: the hex result must fall between the round bar and the metal weight calculator plate value for a square of the same size.

Stainless steel hex bar weight, brass and aluminum

Only the density changes between metals. Carbon and free machining steels such as 1018 and 12L14 sit near 7.85 g/cm³. Stainless steel hex bar weight runs a little higher at about 8.0 g/cm³, so a 20 mm stainless hex weighs 2.771 kg/m against 2.719 for carbon steel. Brass hex bar weight is higher again at about 8.5 g/cm³, 2.944 kg/m for 20 mm, which matters for plumbing fittings turned from brass hex. Aluminum hex bar weight is roughly a third of steel at 2.70 g/cm³, so the same 20 mm bar weighs only 0.935 kg/m. Alloys inside each family shift the density by a percent or two, so treat the result as a close estimate and use the mill certificate when the exact figure decides a price.

Steel hex bar weight chart

Steel hex bar weight from the 0.866 × A² × 7.85 ÷ 1000 formula. Common nut and fitting sizes across flats:

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