12 gauge steel thickness calculator
In the Manufacturers Standard Gauge for steel, 12 gauge is 0.1046 in (2.657 mm). The gauge number counts down as the sheet gets thicker.
Where the neutral axis sits, as a fraction of thickness. 0.33 for tight bends, 0.5 for generous ones.
- Thickness in inches
- 0.104 60
- Weight of the sheet
- 41.712
- Weight per square metre
- 20.856 kg/m2
- Weight per square foot
- 1.9376 kg/ft2
- Minimum inside bend radius One thickness is a safe general rule for mild steel; check the alloy.
- 2.657
- Bend allowance
- 5.926
- Bend deduction
- 4.701
- Suggested V-die opening Eight times thickness is the usual air-bending starting point.
- 21.25
Show the working
- Sheet length = 2000
- Sheet width = 1000
- Steel density = 7850
- Bend angle = 90
- K-factor = 0.42
- Thickness = 2.65684 = 2.656 84
- Thickness in inches = 2.656 84 / 25.4 = 0.1046
- area_m2 = 2000 * 1000 / 1e6 = 2
- volume_m3 = 2 * 2.656 84 / 1000 = 0.005 313 68
- Weight of the sheet = 0.005 313 68 * 7850 = 41.7124
- Weight per square metre = 2.656 84 / 1000 * 7850 = 20.8562
- Weight per square foot = 20.8562 * 0.09290304 = 1.9376
- Minimum inside bend radius = 2.656 84 * 1 = 2.656 84
- Bend allowance = rad(90) * (2.656 84 + 0.42 * 2.656 84) = 5.926 16
- Bend deduction = 2 * (2.656 84 + 2.656 84) * tan(rad(90)/2) - 5.926 16 = 4.7012
- Suggested V-die opening = 2.656 84 * 8 = 21.2547
Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.
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The formula
- weight = length x width x thickness x density
- bend allowance = angle in radians x (inside radius + K x thickness)
- bend deduction = 2 x (inside radius + thickness) x tan(angle/2) - bend allowance
Gauge numbers are not a single standard. Steel, aluminium, stainless and zinc all use different gauge tables for the same number, so always state the material.
The Manufacturers Standard Gauge descends from a weight-per-square-foot table, which is why the thicknesses are not a neat progression.
Frequently asked
How thick is 12 gauge steel?
0.1046 inches, or 2.657 mm, for uncoated sheet steel.
Is a higher gauge number thicker?
No. The gauge number counts down as thickness goes up, so 16 gauge is thicker than 20 gauge.
Where the numbers come from
- Thicknesses are the Manufacturers Standard Gauge for uncoated hot- and cold-rolled sheet steel.