Sheet Metal Gauge Chart: Steel, Stainless & Aluminum

01 / Gauge converter

Start with the metal.
Get the decimal.

Convert a gauge to inches and millimeters, or find the closest gauge to a measured thickness. The selected material stays with you in either direction.

A higher gauge number means a thinner sheet. A gauge match is a reference value, not a measurement tolerance or a stock guarantee.

28

Gauges (3–30)

4

Gauge Standards

126

Stocked SKUs

0.005″

Thinnest We Cut

See every gauge

// Gauge Converter Live

Material

Gauge Number

Gauge values are nominal. Use decimal thickness on your drawing and quote.

// 16 Gauge Mild Steel

0.0598″

1.52 mm · MSG standard

02 / The reference chart

Gauge thickness chart.
Four different metals.

Nominal thickness in each metal, with nearby Xeon catalog stock shown separately. Expand a row for stock and weight details, or choose a green stock chip to open its manufacturing checks. Specify the decimal thickness on your drawing.

Select a gauge to narrow the chart. Expand a row for details; scroll within the table to compare all metals.

Nominal gauge thickness by metal in inches and millimeters, with nearby catalog stock
Gauge Number	Aluminum B&S · ASTM B209	Mild Steel MSG · A1008 / A1011	Stainless MSG SS · ASTM A240	Galvanized MSG Galv · ASTM A653
3▸gauge	0.2294″5.83 mm	0.2391″6.07 mm	0.2500″6.35 mm	—no published gauge
4▸gauge	0.2043″5.19 mm	0.2242″5.69 mm	0.2344″5.95 mm	—no published gauge
5▸gauge	0.1819″4.62 mm	0.2092″5.31 mm	0.2187″5.55 mm	—no published gauge
6▸gauge	0.1620″4.11 mm	0.1943″4.94 mm	0.2031″5.16 mm	—no published gauge
7▸gauge	0.1443″3.67 mm	0.1793″4.55 mm	0.1875″4.76 mm	—no published gauge
8▸gauge	0.1285″3.26 mm	0.1644″4.18 mm	0.1719″4.37 mm	0.1681″4.27 mm
9▸gauge	0.1144″2.91 mm	0.1495″3.80 mm	0.1563″3.97 mm	0.1532″3.89 mm
10▸gauge	0.1019″2.59 mm	0.1345″3.42 mm	0.1406″3.57 mm	0.1382″3.51 mm
11▸gauge	0.0907″2.30 mm	0.1196″3.04 mm	0.1250″3.17 mm	0.1233″3.13 mm
12▸gauge	0.0808″2.05 mm	0.1046″2.66 mm	0.1094″2.78 mm	0.1084″2.75 mm
13▸gauge	0.0720″1.83 mm	0.0897″2.28 mm	0.0938″2.38 mm	0.0934″2.37 mm
14▸gauge	0.0641″1.63 mm	0.0747″1.90 mm	0.0781″1.98 mm	0.0785″1.99 mm
15▸gauge	0.0571″1.45 mm	0.0673″1.71 mm	0.0703″1.79 mm	0.0710″1.80 mm
16▸gauge	0.0508″1.29 mm	0.0598″1.52 mm	0.0625″1.59 mm	0.0635″1.61 mm
17▸gauge	0.0453″1.15 mm	0.0538″1.37 mm	0.0563″1.43 mm	0.0575″1.46 mm
18▸gauge	0.0403″1.02 mm	0.0478″1.21 mm	0.0500″1.27 mm	0.0516″1.31 mm
19▸gauge	0.0359″0.91 mm	0.0418″1.06 mm	0.0438″1.11 mm	0.0456″1.16 mm
20▸gauge	0.0320″0.81 mm	0.0359″0.91 mm	0.0375″0.95 mm	0.0396″1.01 mm
21▸gauge	0.0285″0.72 mm	0.0329″0.84 mm	0.0344″0.87 mm	0.0366″0.93 mm
22▸gauge	0.0253″0.64 mm	0.0299″0.76 mm	0.0313″0.80 mm	0.0336″0.85 mm
23▸gauge	0.0226″0.57 mm	0.0269″0.68 mm	0.0281″0.71 mm	0.0306″0.78 mm
24▸gauge	0.0201″0.51 mm	0.0239″0.61 mm	0.0250″0.64 mm	0.0276″0.70 mm
25▸gauge	0.0179″0.45 mm	0.0209″0.53 mm	0.0219″0.56 mm	0.0247″0.63 mm
26▸gauge	0.0159″0.40 mm	0.0179″0.45 mm	0.0188″0.48 mm	0.0217″0.55 mm
27▸gauge	0.0142″0.36 mm	0.0164″0.42 mm	0.0172″0.44 mm	0.0202″0.51 mm
28▸gauge	0.0126″0.32 mm	0.0149″0.38 mm	0.0156″0.40 mm	0.0187″0.47 mm
29▸gauge	0.0113″0.29 mm	0.0135″0.34 mm	0.0141″0.36 mm	0.0172″0.44 mm
30▸gauge	0.0100″0.25 mm	0.0120″0.30 mm	0.0125″0.32 mm	0.0157″0.40 mm

Gauge thicknesses are nominal reference values from the published standard for each metal. Mill tolerance still applies — ASTM B209 for aluminum, A1008/A1011 for carbon steel, A480 for stainless, A653 for galvanized. Galvanized thicknesses include the zinc coating; the standard has no published gauge below 8. The green stock chips show the actual decimal thickness we hold, which is what we cut and what we quote.

Quick reference / Mild steel

Common steel gauge thicknesses.

Find a quick answer for uncoated carbon steel. Use the four-material chart for stainless, aluminum, or galvanized steel; the same gauge number does not mean the same thickness.

How thick is 10 gauge steel?

0.1345 in3.42 mm

10 gauge mild steel is 0.1345 inches (3.42 mm) nominal. This value is for uncoated carbon steel; stainless steel, galvanized steel, and aluminum use different thicknesses for the same gauge.

How thick is 11 gauge steel?

0.1196 in3.04 mm

11 gauge mild steel is 0.1196 inches (3.04 mm) nominal. This value is for uncoated carbon steel; stainless steel, galvanized steel, and aluminum use different thicknesses for the same gauge.

How thick is 12 gauge steel?

0.1046 in2.66 mm

12 gauge mild steel is 0.1046 inches (2.66 mm) nominal. This value is for uncoated carbon steel; stainless steel, galvanized steel, and aluminum use different thicknesses for the same gauge.

How thick is 14 gauge steel?

0.0747 in1.90 mm

14 gauge mild steel is 0.0747 inches (1.90 mm) nominal. This value is for uncoated carbon steel; stainless steel, galvanized steel, and aluminum use different thicknesses for the same gauge.

How thick is 16 gauge steel?

0.0598 in1.52 mm

16 gauge mild steel is 0.0598 inches (1.52 mm) nominal. This value is for uncoated carbon steel; stainless steel, galvanized steel, and aluminum use different thicknesses for the same gauge.

How thick is 18 gauge steel?

0.0478 in1.21 mm

18 gauge mild steel is 0.0478 inches (1.21 mm) nominal. This value is for uncoated carbon steel; stainless steel, galvanized steel, and aluminum use different thicknesses for the same gauge.

How thick is 20 gauge steel?

0.0359 in0.91 mm

20 gauge mild steel is 0.0359 inches (0.91 mm) nominal. This value is for uncoated carbon steel; stainless steel, galvanized steel, and aluminum use different thicknesses for the same gauge.

How thick is 22 gauge steel?

0.0299 in0.76 mm

22 gauge mild steel is 0.0299 inches (0.76 mm) nominal. This value is for uncoated carbon steel; stainless steel, galvanized steel, and aluminum use different thicknesses for the same gauge.

Nominal inch values use the same data as the converter. Millimeters are calculated from those values and rounded to two decimals. See the reference and rounding notes.

03 / Before you specify

The metal changes the number.

Use the column for the material you intend to buy. The nominal number and the catalog thickness can differ, even before mill tolerance is considered.

!

Aluminum gauge runs on a different standard than steel.

Choosing material for a formed part? Compare 5052-H32 and 6061-T6 aluminum, then use the sheet metal prototyping checklist to specify thickness, bends and inspection requirements together.

Aluminum sheet is gauged on the Brown & Sharpe (AWG) scale. Carbon steel uses the Manufacturers’ Standard Gauge. They are not interchangeable, and the gap widens as the sheet gets thicker:

16 ga aluminum = 0.0508″ but 16 ga mild steel = 0.0598″ — about an 18% difference in thickness. Stiffness and bend force also depend on the material and geometry.

For example, this chart lists 14 gauge aluminum at 0.0641 inches. A 0.063-inch aluminum sheet is a nearby decimal stock thickness, not exactly the same nominal value. Specify which dimension your part requires.

The fix is simple: specify aluminum by decimal thickness. Put 0.063″ on the drawing and in the quote, never “16 ga.” Every aluminum SKU in our catalog carries its decimal thickness for exactly this reason, and the instant quote prices off the decimal. Where you see a gauge number next to an aluminum thickness on this site, treat it as a shop-floor shorthand, not a spec.

04 / Compare thicknesses

See the difference, to scale.

Numbers on a chart flatten out. Stack the gauges next to each other at true relative thickness — against a dime, a credit card, a sheet of paper — and the choice between 14 and 18 gauge stops being abstract.

// Pick gauges to compare

// Material

// Reference lines

Choose up to six gauges. All bars share the same scale; reference objects are approximate.

Scale 900 px / inch

05 / Choose a starting point

Start here, then move a gauge either way.

Gauge is a trade between stiffness, weight, bend force, and cost. These bands are where most laser-cut sheet metal parts land. Thicknesses shown are mild steel — use the chart above to convert for your metal.

7–10Heavy

0.179″ – 0.135″

Structural & load-bearing

Compare these thicknesses for mounting plates, frames, and brackets. Capacity still depends on the material, span, joints, and loads; a gauge number alone does not qualify a load-bearing design.

11–14Workhorse

0.120″ – 0.075″

General fabrication

Compare these thicknesses for brackets, chassis, and enclosures. Check both finished stiffness and the support available during forming before choosing the stock.

16–18Default

0.060″ – 0.048″

Panels, covers, brackets

Useful options to compare for covers, panels, and light brackets. Check unsupported spans, fastening method, finish, and bend geometry rather than selecting on gauge alone.

20–24Light

0.036″ – 0.024″

Housings & interior panels

Consider for lightweight covers, decorative panels, and shields. Large unsupported faces may need stiffening features; review flatness and handling requirements.

26–30Thin

0.018″ – 0.012″

Shims, flashing, non-structural

Thin sheet can suit shims, trim, and shielding. Review handling, cut quality, and thickness tolerance for the specific alloy and application.

06 / Xeon NC stock

The thicknesses we actually hold.

Compare decimal thicknesses listed in the Xeon NC catalog. Catalog entries and tooling references support design planning; confirm current availability and the manufacturing setup in your quote.

Live in the instant quote Stocked — quote on request

07 / Common questions

Sheet metal gauge, answered.

Compare gauge numbers, convert to millimeters, and separate nominal thickness from the requirements on your drawing.

Is 14 gauge steel thicker than 16 gauge?

Yes. For mild steel, 14 gauge is 0.0747 inches (1.90 mm), while 16 gauge is 0.0598 inches (1.52 mm). The 14-gauge sheet is about 25% thicker. This compares thickness only; the part’s stiffness and strength also depend on material, geometry, and support.

Is 16 gauge steel thicker than 18 gauge?

Yes. For mild steel, 16 gauge is 0.0598 inches (1.52 mm), and 18 gauge is 0.0478 inches (1.21 mm). Within the same gauge system, the lower gauge number is thicker.

How do I convert sheet metal gauge to millimeters?

First look up the nominal inch thickness for the correct material. Then multiply that thickness by 25.4. For example, 16 gauge mild steel is 0.0598 inches × 25.4 = 1.51892 mm, or 1.52 mm rounded. Do not multiply the gauge number itself by 25.4.

Does a higher gauge number mean thicker or thinner metal?

A higher gauge number means thinner sheet within the same gauge system. For example, 10 gauge mild steel is thicker than 14 gauge, and 14 gauge is thicker than 18 gauge. Select the material before comparing numbers.

Why is 18 gauge steel a different thickness than 18 gauge aluminum?

Gauge tables are material-specific. This chart lists 18 gauge mild steel at 0.0478 inches, stainless steel at 0.0500 inches, aluminum at 0.0403 inches, and galvanized steel at 0.0516 inches. Specify the material and decimal thickness together so a gauge number cannot be mistaken for another metal’s thickness.

What gauge is most common for laser-cut sheet metal parts?

14, 16, and 18 gauge mild steel are useful starting points when comparing panels, covers, and brackets. Select the actual thickness for the part’s loads, unsupported span, stiffness, joints, and forming requirements. No gauge number by itself qualifies a structural part.

Should I put the gauge or the decimal thickness on my drawing?

Specify the material and decimal thickness, with the required tolerance or applicable material specification. A gauge label can be added as a reference. For example, 16 gauge mild steel is nominally 0.0598 inches; a 0.060-inch catalog option is a nearby decimal thickness, not an identical dimension.

Is gauge thickness the same as the tolerance I will get?

No. A gauge chart gives nominal thickness, not a tolerance. Permitted thickness variation depends on the material specification, product form, dimensions, and order requirements. State any critical thickness limits and confirm them with the fabricator before ordering.

Will a tapped thread hold in this gauge?

Thread suitability depends on engagement length, fastener size, material, and loading. Use the tap drill size chart for planning, and review threaded joints in thin sheet when engagement is limited. Self-clinching hardware may be an option; screening rules are not a strength qualification.

Does gauge change how tight I can bend the part?

Thickness affects tooling choice, flange support, and forming force. Alloy, temper, grain direction, bend angle, and tool geometry also matter. The chart’s stock details provide planning references; confirm the setup using the sheet metal bend radius guide and a manufacturing review.

What does the green chip in the chart mean?

It identifies a nearby decimal thickness from Xeon’s catalog, which can differ from the nominal gauge value. For example, 16 gauge aluminum is listed at 0.0508 inches, while a nearby catalog option is 0.050 inches. Open the chip to review its material and manufacturing information, and confirm availability in the quote.

08 / Reference notes

Nominal gauge. Measured thickness.

The chart uses common U.S. sheet-metal gauge references. It is not a wire, tube-wall, or thickness-tolerance chart.

Read the value in context

Steel, stainless, galvanized steel, and aluminum have separate columns. Values are nominal, and some suppliers round them differently. The displayed millimeter values are converted from this chart’s inch values using 25.4 mm per inch.

Gauge does not specify grade, temper, coating, or allowable thickness variation. For a fit or tolerance stack, use the ordered decimal thickness and the applicable supplier specification.

References and next steps

Need a cut or bent part? Send a DXF or STEP with the material and required thickness for a sheet metal quote.

Choose the thickness.
Make the part.

Get an instant quote

Bring your DXF or STEP file and specify your material by its decimal thickness.

Start with the metal.Get the decimal.

Gauge thickness chart.Four different metals.