Sheet Metal Gauge Thickness Chart
The Gauge system is inverse: higher numbers represent thinner material. Note: Gauge 16 Steel (0.0598") is not the same as Gauge 16 Aluminum (0.0508"). Always specify decimal equivalents in production.
| Gauge # | Standard Steel (inch) | Standard Steel (mm) | Galvanized (inch) | Galvanized (mm) | Stainless (inch) | Stainless (mm) | Aluminum (inch) | Aluminum (mm) |
|---|---|---|---|---|---|---|---|---|
| 30 | 0.0120 | 0.30 | 0.0157 | 0.40 | 0.0125 | 0.32 | 0.0100 | 0.25 |
| 28 | 0.0149 | 0.38 | 0.0187 | 0.47 | 0.0156 | 0.40 | 0.0126 | 0.32 |
| 26 | 0.0179 | 0.45 | 0.0217 | 0.55 | 0.0187 | 0.48 | 0.0159 | 0.40 |
| 24 | 0.0239 | 0.61 | 0.0276 | 0.70 | 0.0250 | 0.64 | 0.0201 | 0.51 |
| 22 | 0.0299 | 0.76 | 0.0336 | 0.85 | 0.0312 | 0.79 | 0.0253 | 0.64 |
| 20 | 0.0359 | 0.91 | 0.0396 | 1.01 | 0.0375 | 0.95 | 0.0320 | 0.81 |
| 18 | 0.0478 | 1.21 | 0.0516 | 1.31 | 0.0500 | 1.27 | 0.0403 | 1.02 |
| 16 | 0.0598 | 1.52 | 0.0635 | 1.61 | 0.0625 | 1.59 | 0.0508 | 1.29 |
| 14 | 0.0747 | 1.90 | 0.0785 | 1.99 | 0.0781 | 1.98 | 0.0641 | 1.63 |
| 13 | 0.0897 | 2.28 | 0.0934 | 2.37 | 0.0937 | 2.38 | 0.0720 | 1.83 |
| 12 | 0.1046 | 2.66 | 0.1084 | 2.75 | 0.1094 | 2.78 | 0.0808 | 2.05 |
| 11 | 0.1196 | 3.04 | 0.1233 | 3.13 | 0.1250 | 3.18 | 0.0907 | 2.30 |
| 10 | 0.1345 | 3.42 | 0.1382 | 3.51 | 0.1406 | 3.57 | 0.1019 | 2.59 |
| 9 | 0.1495 | 3.80 | 0.1532 | 3.89 | 0.1562 | 3.97 | 0.1144 | 2.91 |
| 8 | 0.1644 | 4.18 | 0.1681 | 4.27 | 0.1719 | 4.37 | 0.1285 | 3.26 |
| 7 | 0.1793 | 4.55 | - | - | 0.1875 | 4.76 | 0.1443 | 3.67 |
Engineering Summary: Common Fabrication Gauges
| Gauge # | Carbon Steel (in) | Stainless Steel (in) | Carbon Steel (mm) | Application |
|---|---|---|---|---|
| 10 Gauge | 0.1345" | 0.1406" | 3.42 | High-load brackets |
| 14 Gauge | 0.0747" | 0.0781" | 1.90 | Cabinetry, furniture |
| 16 Gauge | 0.0598" | 0.0625" | 1.52 | Automotive, panels |
| 20 Gauge | 0.0359" | 0.0375" | 0.91 | Dust-work, shielding |
Professional Sheet Metal Gauge Reference for Manufacturing & Design
Practical Example
When transitioning a design from 16-gauge Carbon Steel (0.0598") to 16-gauge Aluminum (0.0508"), keep in mind that the same gauge number does NOT mean the same thickness across different materials. Always refer to the specific material's gauge table to avoid fitment errors in fabrication.
Navigating the world of sheet metal fabrication requires a precise understanding of material thickness. A Sheet Metal Gauge Chart is the standard industry tool used to translate "gauge numbers" into exact decimal dimensions in inches or millimeters. Because "Gauge" is a non-linear measurement system, having an authoritative reference is critical for designers, engineers, and fabricators to ensure structural integrity and assembly precision.
Understanding Gauge: Why Higher Numbers Mean Thinner Metal
The gauge system has its roots in the wire-drawing industry of the 19th century. Historically, the gauge number referred to the number of drawing steps required to reach a specific thickness. Therefore, as the gauge number increases, the material becomes thinner. For example, 10 Gauge Steel is approximately 3.42mm thick, while 20 Gauge Steel is only 0.91mm thick.
The Gauge Paradox
Historically, gauge indicated the number of drawing steps. More steps = thinner wire/sheet. Higher Number = Thinner Metal.
Material Standard Variance
Gauge measurements vary by density. At 16 Gauge:
Steel: 0.0598"
Aluminum: 0.0508"
Galvanized: 0.0635"
Selection Guide: Choosing the Right Gauge for Your Project
Selecting the correct material thickness involves balancing weight, strength, and cost:
- Structural Fabrication (7-11 Gauge): Ideal for heavy-duty brackets, machinery bases, and chassis components.
- General Enclosures (14-18 Gauge): The "sweet spot" for electrical boxes, HVAC ducting, and automotive body panels.
- Precision Components (20-26 Gauge): Used for internal clips, decorative panels, and lightweight shielding.
Manufacturing Tolerances and Industry Standards
It is important to note that manufacturers operate within ASTM tolerances. A sheet of 16-gauge steel may vary slightly from its nominal decimal value depending on the mill's specific production standards. For high-precision aerospace or medical applications, engineers typically specify material by the absolute decimal thickness rather than the gauge number to avoid ambiguity.
By referring to this comprehensive sheet metal gauge chart, you can confidently specify materials that meet your mechanical requirements, optimize your supply chain, and ensure consistent quality in every fabricated part.