8 gauge steel thickness calculator
In the Manufacturers Standard Gauge for steel, 8 gauge is 0.1644 in (4.176 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
- 0.164 40
- Weight of the sheet
- 65.559
- Weight per square metre
- 32.780 kg/m2
- Weight per square foot
- 3.0453 kg/ft2
- Minimum inside bend radius One thickness is a safe general rule for mild steel; check the alloy.
- 4.176
- Bend allowance
- 9.314
- Bend deduction
- 7.389
- Suggested V-die opening Eight times thickness is the usual air-bending starting point.
- 33.41
Show the working
- Sheet length = 2000
- Sheet width = 1000
- Steel density = 7850
- Bend angle = 90
- K-factor = 0.42
- Thickness = 4.1757599999999995 = 4.175 76
- Thickness in inches = 4.175 76 / 25.4 = 0.1644
- area_m2 = 2000 * 1000 / 1e6 = 2
- volume_m3 = 2 * 4.175 76 / 1000 = 0.008 351 52
- Weight of the sheet = 0.008 351 52 * 7850 = 65.5594
- Weight per square metre = 4.175 76 / 1000 * 7850 = 32.7797
- Weight per square foot = 32.7797 * 0.09290304 = 3.045 34
- Minimum inside bend radius = 4.175 76 * 1 = 4.175 76
- Bend allowance = rad(90) * (4.175 76 + 0.42 * 4.175 76) = 9.314 16
- Bend deduction = 2 * (4.175 76 + 4.175 76) * tan(rad(90)/2) - 9.314 16 = 7.388 88
- Suggested V-die opening = 4.175 76 * 8 = 33.4061
Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.
Scenarios & local history
Compare a saved scenario
Recent calculations
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 8 gauge steel?
0.1644 inches, or 4.176 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.