4 gauge steel thickness calculator
In the Manufacturers Standard Gauge for steel, 4 gauge is 0.2242 in (5.695 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
- 0.224 20
- Weight of the sheet
- 89.406
- Weight per square metre
- 44.703 kg/m2
- Weight per square foot
- 4.1531 kg/ft2
- Minimum inside bend radius One thickness is a safe general rule for mild steel; check the alloy.
- 5.695
- Bend allowance
- 12.702
- Bend deduction
- 10.077
- Suggested V-die opening Eight times thickness is the usual air-bending starting point.
- 45.56
Show the working
- Sheet length = 2000
- Sheet width = 1000
- Steel density = 7850
- Bend angle = 90
- K-factor = 0.42
- Thickness = 5.69468 = 5.694 68
- Thickness in inches = 5.694 68 / 25.4 = 0.2242
- area_m2 = 2000 * 1000 / 1e6 = 2
- volume_m3 = 2 * 5.694 68 / 1000 = 0.011 389 4
- Weight of the sheet = 0.011 389 4 * 7850 = 89.4065
- Weight per square metre = 5.694 68 / 1000 * 7850 = 44.7032
- Weight per square foot = 44.7032 * 0.09290304 = 4.153 07
- Minimum inside bend radius = 5.694 68 * 1 = 5.694 68
- Bend allowance = rad(90) * (5.694 68 + 0.42 * 5.694 68) = 12.7022
- Bend deduction = 2 * (5.694 68 + 5.694 68) * tan(rad(90)/2) - 12.7022 = 10.0766
- Suggested V-die opening = 5.694 68 * 8 = 45.5574
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 4 gauge steel?
0.2242 inches, or 5.695 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.