Measuring steel sheets, particularly their thickness, is often done using a standardized system known as the gauge system, alongside physical measurement tools. However, a key method involves using a sheet metal gauge chart.
Engineers frequently rely on a sheet metal gauge chart to translate a material's gauge number into its precise thickness in standard units like inches or millimeters. This chart provides a convenient way to understand the thickness without necessarily performing a physical measurement, especially when the gauge is already known.
Understanding the Gauge System
The gauge system is a traditional method for specifying the thickness of sheet metal. It's important to note that higher gauge numbers correspond to thinner sheets, while lower gauge numbers indicate thicker sheets. This can be counter-intuitive compared to standard linear measurements.
Using a Sheet Metal Gauge Chart
To determine the thickness of a steel sheet using its gauge number, you consult a gauge chart. For example, as stated in the reference:
Engineers can use a sheet metal gauge chart to determine the actual thickness of sheet metal in inches or millimeters. An example is 18 gauge steel, which has a thickness of 0.0478 inches or 1.214 millimeters, according to the sheet metal gauge chart.
This illustrates how a specific gauge number (18 gauge) directly corresponds to defined thickness values (0.0478 inches / 1.214 mm) on a gauge chart.
Example Gauge Equivalents for Steel
While specific values can vary slightly depending on the standard (e.g., U.S. Standard Gauge for sheet steel), a chart typically includes entries like this:
| Gauge Number | Thickness (Inches) | Thickness (Millimeters) |
|---|---|---|
| 10 | 0.1345 | 3.416 |
| 14 | 0.0747 | 1.905 |
| 18 | 0.0478 | 1.214 |
| 20 | 0.0359 | 0.912 |
| 24 | 0.0239 | 0.607 |
Note: Values are illustrative and may vary based on specific chart standards.
This table shows how gauge numbers relate to actual thickness, reinforcing that a higher gauge number means a thinner material.
Why Use Gauge?
- Historical Standard: Gauge has been used for a long time in the industry.
- Simplified Specification: It provides a simple number to represent a specific thickness within the system.
- Industry Communication: Fabricators and suppliers often use gauge numbers in orders and specifications.
In summary, while physical tools like micrometers and calipers can directly measure thickness, using a sheet metal gauge chart based on the material's gauge number is a common and essential method for determining the precise thickness of steel sheets, as highlighted by the practice of engineers.
