8 gauge steel thickness and weight
0.1644 in · 4.18 mm · 6.714 lb/ft²
8 gauge sheet steel (Manufacturers' Standard Gauge) is 0.1644 in, or 4.18 mm, thick. It weighs 6.714 lb per square foot (32.78 kg/m²).
Weight of common sheet sizes
| Sheet | lb | kg |
|---|---|---|
| 4 × 8 ft | 214.8 | 97.5 |
| 4 × 10 ft | 268.6 | 121.8 |
| 5 × 10 ft | 335.7 | 152.3 |
| 1000 × 2000 mm | 144.5 | 65.6 |
| 1250 × 2500 mm | 225.8 | 102.4 |
| 1500 × 3000 mm | 325.2 | 147.5 |
8 gauge in other metals
| Material | Thickness (in) | Thickness (mm) | kg/m² |
|---|---|---|---|
| Sheet steel | 0.1644 | 4.18 | 32.78 |
| Galvanized steel | 0.1681 | 4.27 | 33.52 |
| Stainless steel | 0.1719 | 4.37 | 34.62 |
| Aluminum | 0.1285 | 3.26 | 8.81 |
Gauge numbers are tied to the material, so 8 gauge aluminum is not the same thickness as 8 gauge steel. When ordering, give the thickness in inches or millimetres.
Compared with nearby gauges
| Gauge | in | mm | lb/ft² | Thickness vs 8 ga |
|---|---|---|---|---|
| 5 gauge | 0.2092 | 5.31 | 8.543 | +27 % |
| 6 gauge | 0.1943 | 4.94 | 7.935 | +18 % |
| 7 gauge | 0.1793 | 4.55 | 7.322 | +9 % |
| 8 gauge | 0.1644 | 4.18 | 6.714 | — |
| 9 gauge | 0.1495 | 3.80 | 6.105 | −9 % |
| 10 gauge | 0.1345 | 3.42 | 5.493 | −18 % |
| 11 gauge | 0.1196 | 3.04 | 4.884 | −27 % |
A lower gauge number means a thicker sheet. The steps between gauges are not equal, because the gauge system started as a measure of weight per square foot rather than of thickness.
Metric and fractional equivalents
Outside the US, sheet is ordered in millimetres. The nearest standard metric thickness to 8 gauge (4.18 mm) is 4 mm, which weighs 31.40 kg/m². The nearest fraction of an inch is 5/32 in (0.1563 in). If a drawing calls for 8 gauge and you buy metric sheet, check whether the small difference in thickness matters for bending, welding or fit.
Weight of strips
Weight per running foot of a 8 gauge strip, for sheared blanks and formed parts.
| Strip width | lb per foot of length |
|---|---|
| 6 in | 3.36 |
| 12 in | 6.71 |
| 24 in | 13.43 |
| 36 in | 20.14 |
| 48 in | 26.86 |
Where 8 gauge is used
Gauges this heavy are used for truck beds, trailer floors, brackets, machine bases, tanks and heavy guards. Thickness tolerances for cold-rolled and hot-rolled sheet are set by ASTM A568 and depend on width, so the measured thickness can be a few thousandths of an inch off the nominal gauge value.
Frequently asked questions
How thick is 8 gauge steel in mm?
8 gauge sheet steel is 4.18 mm (0.1644 in). The nearest standard metric sheet is 4 mm.
How much does a 4 × 8 sheet of 8 gauge steel weigh?
About 214.8 lb (97.5 kg): 6.714 lb/ft² × 32 ft².
Is 8 gauge thicker than 9 gauge?
Yes. A lower gauge number is thicker: 8 gauge is 0.1644 in, 9 gauge is 0.1495 in, and 7 gauge is 0.1793 in.
Is 8 gauge the same as 5/32 inch?
Close: 8 gauge is 0.1644 in and 5/32 in is 0.1563 in. Material ordered as 5/32 in is made to that fractional thickness, so it is about 5 % thinner than 8 gauge.
How thick is 8 gauge galvanized steel?
0.1681 in (4.27 mm), slightly more than plain 8 gauge because the gauge includes the zinc coating.
Is 8 gauge aluminum the same thickness as steel?
No. 8 gauge aluminum is 0.1285 in (3.26 mm); aluminum uses a different gauge table.
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Data adapted from Wikipedia, "Sheet metal" (CC BY-SA 4.0).