Sheet metal is a versatile material used in a wide range of industries, including construction, automotive, manufacturing, and more. It is crucial to have a clear understanding of sheet metal thickness to ensure proper selection and usage. This is where a sheet metal gauge chart comes into play. In this article, we will explore the significance of a sheet metal gauge chart and provide insights into its interpretation for effective decision-making.
What is a Sheet Metal Gauge Chart?
A sheet metal gauge chart, also known as a sheet metal gauge table or sheet metal thickness chart, is a reference tool that provides a standardized measurement system for sheet metal thickness. It offers a comparison between different gauge numbers and their corresponding thicknesses in inches, millimeters, or other units of measurement. The chart typically lists a range of gauge numbers and their associated thickness values, allowing users to quickly determine the thickness of a specific sheet of metal.
Gauges are used to signify the sheet metal thickness. Using a sheet metal gauge chart, the user can easily convert the mentioned gauge into actual thicknesses in inches or mm. Steel thickness gauges can be used to verify the thickness. To give an example, For example, as per the gauge conversion chart table, 18 gauge steel is 0.0478 inches or 1.214 millimeters. The actual gauge number “18” does not hold any relevance to the actual measurements.
Understanding the Gauge Number System
The gauge number system used in sheet metal gauge charts is based on a numerical sequence, where lower gauge numbers indicate thicker sheets, while higher gauge numbers represent thinner sheets. However, the gauge system is not linear but follows a logarithmic scale. This means that the difference in thickness between two adjacent gauge numbers is not uniform but progressively decreases as the gauge number increases.
Note that, even though gauges are used to specify the thickness they are neither standard nor metric. The thickness values are independent of those measurement systems.
Standard Sheet Metal Gauge Chart
The most commonly used sheet metal gauge chart is based on the U.S. Standard Gauge (USG) system. This system assigns gauge numbers ranging from 1 to 36 to different sheet metal thicknesses. As per the USG system, gauge number 1 represents the thickest sheet metal, while gauge number 36 denotes the thinnest.
Interpreting the Sheet Metal Gauge Chart
When using a sheet metal gauge chart, it is essential to understand its interpretation. Here are a few key points to consider:
Gauge Number: Locate the gauge number on the chart that corresponds to the sheet metal you are working with. This will help you determine its thickness.
Thickness: Identify the thickness value associated with the chosen gauge number. The chart provides thickness measurements in inches, millimeters, or other units.
Conversion: If you are working with a gauge system that differs from the one on the chart, you may need to convert the gauge number to match the chart’s units. Conversion tables are available for this purpose.
Material Variations: Keep in mind that different types of sheet metal materials, such as steel, aluminum, or stainless steel, may have slight variations in thickness for a given gauge number. It’s advisable to consult material-specific charts or industry standards for precise measurements.
Sheet metal gauge charts are not uniform with respect to different metals. This means that gauge 10 for Steel may not be same as the gauge 10 for Aluminum. Some of the sheet metal gauge charts for common materials are provided below:
Sheet Metal Gauge Chart for Mild Steel
Here’s a tabular format of a Sheet Metal Gauge Chart for Mild Steel:
Gauge Number
Thickness (inches)
Thickness (mm)
30
0.0120
0.30
28
0.0149
0.38
26
0.0179
0.45
24
0.0239
0.61
22
0.0299
0.76
20
0.0359
0.91
18
0.0478
1.21
16
0.0598
1.52
14
0.0747
1.90
12
0.1046
2.66
11
0.1196
3.04
10
0.1345
3.42
9
0.1495
3.80
8
0.1644
4.18
7
0.1793
4.55
6
0.1943
4.94
4
0.2242
5.70
2
0.2840
7.21
Table 1: Sheet Metal Gauge Chart for Mild Steel
Please note that these values represent a standard sheet metal gauge chart for mild steel, but there might be slight variations depending on specific manufacturing standards or regional practices. Always consult industry-specific guidelines or materials suppliers for precise measurements and specifications.
Sheet Metal Gauge Chart for Aluminum
The Sheet Metal Gauge Chart for Aluminum is provided in the following table:
Gauge Number
Thickness (inches)
Thickness (mm)
30
0.01003
0.26
28
0.01264
0.32
26
0.01594
0.41
24
0.02010
0.51
22
0.02535
0.64
20
0.03196
0.81
18
0.04030
1.02
16
0.05082
1.29
14
0.06408
1.63
12
0.08081
2.05
10
0.1019
2.59
8
0.1285
3.26
7
0.1443
3.66
Table 2: Aluminum Gauge Chart
Please note that these values represent a standard sheet metal gauge chart for aluminum, but there might be slight variations depending on specific manufacturing standards or regional practices.
The gauge chart for Brass and Stainless Steel is provided in Table 3 below:
Brass Gauge Chart
Stainless Steel Gauge Chart
Gauge Number
Inches
MM
Gauge Number
Inches
MM
8
0.1285
3.264
8
0.1719
4.365
9
0.1144
2.906
9
0.1563
3.968
10
0.1019
2.588
10
0.1406
3.571
11
0.09074
2.305
11
0.125
3.175
12
0.08081
2.053
12
0.1094
2.778
14
0.06408
1.628
14
0.0781
1.984
16
0.05082
1.291
16
0.0625
1.587
18
0.0403
1.024
18
0.05
1.27
20
0.03196
0.812
20
0.0375
0.9525
22
0.02535
0.644
22
0.0313
0.7937
24
0.0201
0.511
24
0.025
0.635
26
0.01594
0.405
26
0.0188
0.476
28
0.01264
0.321
28
0.0156
0.396
30
0.01003
0.255
30
0.0125
0.3175
Table 3: Gauge Chart for Brass and Stainless Steel
Table 4 provides the Gauge chart for Copper and Galvanized Steel.
Galvanized Steel Gauge Chart
Copper Gauge Chart
Gauge Number
Inches
MM
Gauge Number
Inches
MM
8
0.1681
4.269
8
0.165
4.191
9
0.1532
3.891
9
0.148
3.759
10
0.1382
3.51
10
0.134
3.404
11
0.1233
3.1318
11
0.12
3.048
12
0.1084
2.753
12
0.109
2.769
14
0.0785
1.9939
14
0.083
2.108
16
0.0635
1.6129
16
0.065
1.651
18
0.0516
1.31
18
0.049
1.245
20
0.0396
1.005
20
0.035
0.889
22
0.0336
0.853
22
0.028
0.711
24
0.0276
0.701
24
0.022
0.559
26
0.0217
0.551
26
0.018
0.457
28
0.0187
0.474
28
0.014
0.356
30
0.0157
0.398
30
0.012
0.305
Table 4: Gauge Chart for Galvanized Steel and Copper
Practical Applications
A sheet metal gauge chart finds applications in various industries, including:
Sheet Metal Fabrication: Sheet metal workers, fabricators, and welders use the gauge chart to select the appropriate thickness for their projects, ensuring structural integrity and meeting design specifications.
Manufacturing: The manufacturing industry relies on accurate thickness measurements for sheet metal parts used in machinery, equipment, and consumer products.
Construction: Builders and contractors refer to the gauge chart to determine the appropriate sheet metal thickness for roofing, siding, ductwork, and other construction applications.
Automotive: In the automotive sector, the gauge chart aids in selecting sheet metal for body panels, frames, and other components, contributing to vehicle safety and performance.
Conclusion
A sheet metal gauge chart serves as a valuable tool for understanding the thickness of sheet metal materials. By providing a standardized measurement system, it allows users to quickly determine the thickness based on gauge numbers. Proper interpretation of the gauge chart is essential for selecting the appropriate sheet metal thickness for various applications. Whether in metal fabrication, manufacturing, construction, or automotive industries, referring to a sheet metal gauge chart helps ensure precision, quality, and compliance with industry standards.
I am a Mechanical Engineer turned into a Piping Engineer. Currently, I work in a reputed MNC as a Senior Piping Stress Engineer. I am very much passionate about blogging and always tried to do unique things. This website is my first venture into the world of blogging with the aim of connecting with other piping engineers around the world.
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