9 gauge steel thickness and weight
0.1495 in · 3.80 mm · 6.105 lb/ft²
9 gauge sheet steel (Manufacturers' Standard Gauge) is 0.1495 in, or 3.80 mm, thick. It weighs 6.105 lb per square foot (29.81 kg/m²).
Weight of common sheet sizes
| Sheet | lb | kg |
|---|---|---|
| 4 × 8 ft | 195.4 | 88.6 |
| 4 × 10 ft | 244.2 | 110.8 |
| 5 × 10 ft | 305.3 | 138.5 |
| 1000 × 2000 mm | 131.4 | 59.6 |
| 1250 × 2500 mm | 205.4 | 93.2 |
| 1500 × 3000 mm | 295.7 | 134.1 |
9 gauge in other metals
| Material | Thickness (in) | Thickness (mm) | kg/m² |
|---|---|---|---|
| Sheet steel | 0.1495 | 3.80 | 29.81 |
| Galvanized steel | 0.1532 | 3.89 | 30.55 |
| Stainless steel | 0.1563 | 3.97 | 31.48 |
| Aluminum | 0.1144 | 2.91 | 7.85 |
Gauge numbers are tied to the material, so 9 gauge aluminum is not the same thickness as 9 gauge steel. When ordering, give the thickness in inches or millimetres.
Compared with nearby gauges
| Gauge | in | mm | lb/ft² | Thickness vs 9 ga |
|---|---|---|---|---|
| 6 gauge | 0.1943 | 4.94 | 7.935 | +30 % |
| 7 gauge | 0.1793 | 4.55 | 7.322 | +20 % |
| 8 gauge | 0.1644 | 4.18 | 6.714 | +10 % |
| 9 gauge | 0.1495 | 3.80 | 6.105 | — |
| 10 gauge | 0.1345 | 3.42 | 5.493 | −10 % |
| 11 gauge | 0.1196 | 3.04 | 4.884 | −20 % |
| 12 gauge | 0.1046 | 2.66 | 4.272 | −30 % |
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 9 gauge (3.80 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 9 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 9 gauge strip, for sheared blanks and formed parts.
| Strip width | lb per foot of length |
|---|---|
| 6 in | 3.05 |
| 12 in | 6.11 |
| 24 in | 12.21 |
| 36 in | 18.32 |
| 48 in | 24.42 |
Where 9 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 9 gauge steel in mm?
9 gauge sheet steel is 3.80 mm (0.1495 in). The nearest standard metric sheet is 4 mm.
How much does a 4 × 8 sheet of 9 gauge steel weigh?
About 195.4 lb (88.6 kg): 6.105 lb/ft² × 32 ft².
Is 9 gauge thicker than 10 gauge?
Yes. A lower gauge number is thicker: 9 gauge is 0.1495 in, 10 gauge is 0.1345 in, and 8 gauge is 0.1644 in.
Is 9 gauge the same as 5/32 inch?
Close: 9 gauge is 0.1495 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 % thicker than 9 gauge.
How thick is 9 gauge galvanized steel?
0.1532 in (3.89 mm), slightly more than plain 9 gauge because the gauge includes the zinc coating.
Is 9 gauge aluminum the same thickness as steel?
No. 9 gauge aluminum is 0.1144 in (2.91 mm); aluminum uses a different gauge table.
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Data adapted from Wikipedia, "Sheet metal" (CC BY-SA 4.0).