--- type: "hub" name: "Sheet metal gauge reference" material_count: 4 gauge_count: 136 materials: ["aluminum", "galvanized", "steel", "us-standard"] standard: "15 U.S.C. 206; Manufacturers' Standard Gauge; Brown & Sharpe / AWG" verified: "August 1, 2026" url: https://shopmath.org/gauges --- # Sheet Metal Gauge Reference — Thickness by Material and Gauge System 136 gauge-to-thickness entries across 4 materials. Gauge is a numbering scheme, not a unit: 16 gauge steel is 0.0598 in while 16 gauge aluminium is 0.0508 in, because each material carries its own gauge system. ## Gauge Systems by Material | Material | Gauge system | Gauges | Thickest | Thinnest | What it covers | | --- | --- | --- | --- | --- | --- | | [Sheet Aluminium](https://shopmath.org/gauges/aluminum.md) | B&S | 33 | [3 ga](https://shopmath.org/gauges/aluminum/3.md) — 0.2294 in | [35 ga](https://shopmath.org/gauges/aluminum/35.md) — 0.0056 in | Aluminium and other non-ferrous sheet on the Brown & Sharpe geometric series. | | [Galvanized Steel](https://shopmath.org/gauges/galvanized.md) | galvanized-MSG | 24 | [9 ga](https://shopmath.org/gauges/galvanized/9.md) — 0.1532 in | [32 ga](https://shopmath.org/gauges/galvanized/32.md) — 0.0135 in | Galvanized sheet — MSG steel thickness plus a 2.5 oz/ft2 zinc coating allowance. | | [Sheet Steel](https://shopmath.org/gauges/steel.md) | MSG | 34 | [3 ga](https://shopmath.org/gauges/steel/3.md) — 0.2391 in | [36 ga](https://shopmath.org/gauges/steel/36.md) — 0.0067 in | Mild, cold-rolled and hot-rolled sheet steel on the Manufacturers' Standard Gauge. | | [U.S. Standard Gauge](https://shopmath.org/gauges/us-standard.md) | USG | 45 | [0000000 ga](https://shopmath.org/gauges/us-standard/0000000.md) — 0.5000 in | [38 ga](https://shopmath.org/gauges/us-standard/38.md) — 0.0063 in | The 1893 statutory gauge, as enacted, on a wrought-iron density basis. | _A material appears here only when it carries at least three verified gauges._ ## Common Gauges Across Every Material The same gauge number, side by side. This is the comparison the numbering scheme hides. | Gauge | Aluminium | Galvanized | Steel | US Standard | | --- | --- | --- | --- | --- | | 10 ga | 0.1019 in / 2.588 mm | 0.1382 in / 3.511 mm | 0.1345 in / 3.416 mm | 0.1406 in / 3.572 mm | | 12 ga | 0.0808 in / 2.053 mm | 0.1084 in / 2.752 mm | 0.1046 in / 2.657 mm | 0.1094 in / 2.778 mm | | 14 ga | 0.0641 in / 1.628 mm | 0.0785 in / 1.993 mm | 0.0747 in / 1.898 mm | 0.0781 in / 1.984 mm | | 16 ga | 0.0508 in / 1.291 mm | 0.0635 in / 1.613 mm | 0.0598 in / 1.518 mm | 0.0625 in / 1.587 mm | | 18 ga | 0.0403 in / 1.024 mm | 0.0516 in / 1.310 mm | 0.0478 in / 1.215 mm | 0.0500 in / 1.270 mm | | 20 ga | 0.0320 in / 0.812 mm | 0.0396 in / 1.006 mm | 0.0359 in / 0.911 mm | 0.0375 in / 0.953 mm | | 22 ga | 0.0253 in / 0.644 mm | 0.0336 in / 0.854 mm | 0.0299 in / 0.759 mm | 0.0313 in / 0.794 mm | | 24 ga | 0.0201 in / 0.511 mm | 0.0276 in / 0.702 mm | 0.0239 in / 0.607 mm | 0.0250 in / 0.635 mm | ## Sources and Method for the Sheet Metal Gauge Data ### Sheet-metal gauge thicknesses — steel, galvanized, aluminium, US Standard - **Source**: 15 U.S.C. 206 statutory weights (public domain); MSG, galvanized and Brown & Sharpe formulas - **Method**: computed - **Verified against**: gauges: 137 checks passed across 1 harness(es) ### Assumptions - Gauge is a numbering scheme, not a unit. A thickness is only meaningful with its material and gauge system stated. - Sheet is supplied to a mill tolerance around these nominal thicknesses. - Dataset scope: EXCLUDED: stainless steel (genuinely ambiguous convention, only one source in hand), zinc, copper, brass, steel tube wall. **Data last verified**: August 1, 2026 ## Related pages - Full cross-material chart: [Sheet metal gauge chart](https://shopmath.org/charts/sheet-metal-gauge.md) - Drill sizes: [Drill bit size reference](https://shopmath.org/drills.md) --- *Source: [ShopMath](https://shopmath.org/gauges) — data verified August 1, 2026. Reference data; verify against the governing standard before manufacture.*