What Will One Blank Weigh?
Pick one of seven shapes or a DXF file, enter its size and gauge, and get the weight of one blank and the whole order in carbon steel, its cut length, and the coil steel to buy.
How It's Calculated
- Circle area
- π × diameter² ÷ 4
- Ring area
- π × (outside diameter² − hole diameter²) ÷ 4
- Slot
- (length − width) × width + π × width² ÷ 4
- Trapezoid
- (long side + short side) ÷ 2 × height
- Hexagon
- √3 ÷ 2 × across the flats²
- Circle with flats
- circle area less the two segments the flats cut off
- L-shape
- width × bottom leg + (height − bottom leg) × side leg
- Weight
- area × gauge × 0.2836 lb per cubic inch
- Weight range
- area × (gauge ± tolerance) × 0.2836
- Steel to buy
- quantity × coil width × gauge × 0.2836 ÷ blanks per inch of coil
Related: What Gauge Means · Lift Planner · Blanking
Questions About Blank Weight
How do you calculate the weight of a steel blank?
Multiply the flat area of the blank by its thickness to get its volume in cubic inches, then by the density of steel. Carbon steel weighs about 0.2836 lb per cubic inch, which is 490 lb per cubic foot.
Can I use my own part drawing?
Yes. Choose From a DXF File under Shape and pick the file. It is read on your computer, not uploaded: the outline and holes are found, and lines on border, title block, dimension and note layers are left out. If the numbers look right, Quote These Numbers attaches the same file to your quote request. Use a flat pattern, not a formed part, and check the drawing above matches your part.
Why does the real weight differ from the calculated weight?
Steel is never exactly the nominal gauge. Mills roll to a tolerance, coils can be thicker in the middle than at the edges, and coatings such as galvanizing add weight. The thinnest and thickest weights show how far the gauge tolerance alone can move the number.
What is the difference between gauge and thickness?
A gauge number is an old shorthand for a thickness: the higher the number, the thinner the steel. 12 gauge sheet steel is 0.1046 in, 14 gauge is 0.0747 in. Most prints today call out the decimal thickness, and this calculator works in decimals.
Why buy more steel than the blanks weigh?
Blanks are cut from a coil, and the skeleton between them and the strip along each edge become scrap. How much depends on the nest. A circle cut from a coil rarely uses more than about 80% of the steel, so the steel to buy is always more than the order weighs.