sheet metal gauge

An Overview of Sheet Metal Gauge Chart

Sheet metal is one of the common building materials used in construction, metalworking, and even home repair projects. Since sheet metal comes in various material types, they also vary in thickness. The thickness of sheet metal is expressed in “gauge”. Understanding the sheet metal gauge chart is critical to determining the metal thickness required for your fabrication project.

This article explains what sheet metal gauge is and its importance. It also explains how to measure the thickness and choose the right sheet metal gauge for your project. Let us get started.

What is Sheet Metal Gauge?

A sheet metal gauge indicates the standard thickness for a specific material, such as steel, copper, and aluminum. The higher the gauge number, the thinner the material, and the lower the gauge number, the thicker the material. For example, a gauge of 7 is going to be thicker than a gauge of 10 or a gauge of 12. The metal fabrication industry often uses sheet steel from 30 gauge (thinner) to 7 gauge (thicker) in gauges. 

It’s very important to choose sheet metal with the right gauge. An incorrect sheet metal gauge can have a minor or significant impact on your part performance. 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.

Generally, sheet metal tools are used to measure the thickness of metal materials. There are different sheet metal tools for ferrous and nonferrous metals because they have the same gauges but different thicknesses. The corresponding thickness for 8 gauge mild steel is 0.1644 inches, while its equivalent galvanized steel gauge (gauge 8) is 0.1681 inches. 

How does Sheet Metal Gauge Work?

A sheet metal gauge chart includes the gauge number and the thickness of a certain metal in inches or millimeters. When reading a sheet metal gauge chart, you should keep the following principles in mind:

  1. You can use the sheet metal gauge chart to confirm metal thickness for CNC machining. 
  2. The numbers in the sheet metal gauge chart are unrelated to the measurement system and do not represent actual measured values. 
  3. The same gauge number for various materials results in different thicknesses. For example, 37 gauge stainless steel has a thickness of 0.0066 inches, whereas 37 gauge aluminum has a thickness of 0.0045 inches.
  4. The material has different gauge standards. The standard is developed based on the weight of the sheet for a given material. 

The Importance of Sheet Metal Gauge

There is a risk in fabricating a part without considering the thickness or gauge of the metal. Incorrect sheet metal gauge can have minor or catastrophic effects on the application of the part. Here are reasons why sheet metal gauges are so important:

Determine the Required Thickness

A sheet metal gauge is important in determining the required thickness of the metal sheet. When you don’t get the correct measurement for that required sheet metal, it can help you take the guesswork out of what thickness of material to use. Knowing the right material thickness will help you set up your welding machine.

Ensure the Durability of the Part

How long a part will last depends mainly on the gauge of the metal used. Some parts require thick metal with high strength, while others do not. Therefore, the part’s durability depends on the gauge of the metal.

Save Production and Shipping Costs

Not all parts need thick metal. Moreover, too dense or too much metal will increase production and shipping costs. The sheet metal gauge can help you choose the appropriate metal thickness to save costs for your project.

Prevent Structural Problems and Deformation

Using too thin metal in a particular design may cause structural problems or deformation of the parts. A sheet metal gauge chart can help you confirm the required metal thickness and avoid this situation.

The History of Sheet Metal Gauge

The word ‘gauge’ is derived from and related to the French word ‘jauge’, which means ‘result of measurement’. Gauges are old measures of thickness. Let us take a closer look at the history of sheet metal gauges: 

– Gauges originated in the British iron wire industry when no universal unit of thickness existed.

– The size of the gauge numbers resulted from the wire drawing process and the properties of iron as a substance. 

– In the 19th century, gauges were measured and described in fractions of an inch.

– In the UK, one gauge was standardized and legally required as the Standard Wire Gauge. Providing convenience for craftsmen was a critical factor in the standardization of the gauge.

– In the 20th century, the International System of Units was supposed to replace the gauge — which ultimately did not occur.

– In the 21st century, the craftsmen like anesthetists seem to find it difficult to remove the gauge from their minds.

The History of Sheet Metal Gauge

How to Measure Sheet Metal Thickness?

After you understand a sheet metal gauge, you should learn how to measure the thickness of sheet metal. The sheet metal thickness can be measured using regular tape or a gauge wheel.

#1: Measuring Sheet Metal Thickness with Regular Tape

There are three simple steps to measure a sheet metal thickness with regular tape, and they include:

Step 1

Firstly, you can use the millimeter hash marks on your regular tape to determine the sheet metal thickness. Remember that your tape has two measurements, namely cm and mm. Using the former will not offer the precise measurements you desire.

Step 2

Then, you can convert the number measured in mm to inches. Simply put, multiply the number in mm by 0.03937 to get the number in inches. For example, if you have a 60mm measurement, multiply it by 0.03937 to get 2.3622 inches.

Step 3

Finally, compare your result in inches to a sheet metal gauge chart. You’ll be able to determine the appropriate metal gauge this way.

#2: Measuring Sheet Metal Thickness with a Gauge Wheel

A gauge wheel is a simple tool with no moving parts. It can usually be used to measure wire and sheet metal. There are three steps involved in measuring sheet metal thickness with a gauge wheel:

Step 1

If you are measuring a nonferrous metal (metals without iron) such as gold, silver, or copper, make sure the front of the gauge wheel reads “nonferrous metal.” 

Likewise, you want to determine the sheet metal gauge for ferrous metals (iron-containing metals) such as stainless steel, cast iron, etc. In this case, you must choose a gauge wheel that reads “ferrous metal” to measure. Using the right gauge wheel can get a correct measurement.

Step 2

There are various-sized gaps surrounding the gauge wheel. Each gap has a number put in front of it. The specific operation is to place your metal piece in each gap until you find a place where it fits perfectly. Note that the round cutout below the gaps is not the right one to use. Please use the gaps at the top instead.

Step 3

Once you’ve determined which gap the metal fits in, check the number in the front of the gap. For instance, if your metal piece fits in a gap with the number 16 written in the front, it is a 16 gauge metal.

Common Types of Sheet Metal

Determining the correct gauge for your project starts with selecting the correct type of sheet metal. We’ll list some features of the industry’s most commonly used sheet metals so you can determine which material is best for your needs.

Steel

Steel is an alloy composed of iron with the addition of carbon. Steel can be used in buildings, infrastructure, tools, vehicles, machinery, electrical appliances, weapons, and rockets due to its high tensile strength and low cost.

Features of Steel:

  • The cheapest metal.
  • It has properties almost similar to other metals.
  • Has structural integrity (can withstand temperatures up to 1000 ℃).
  • Need protection against rust and corrosion.
  • Difficult to cut compared with aluminum.

Galvanized Steel

Galvanized steel is one of the most popular steel types due to its long durability, the strength and formability of steel, and the corrosion protection provided by the zinc-iron coating. Galvanized steel can be used in various projects and industries, including agriculture, solar, automotive, construction, etc.

Features of Galvanized Steel:

  • Longer life.
  • Low initial cost compared to most treated steels.
  • It resists corrosion from the elements.   
  • Often used in recesses that can’t be covered with paint and other protective coatings.
  • It requires less preparation before you can use it.

Stainless Steel

Stainless steel is a steel alloy that is appealing, durable, corrosion-resistant, and easy to fabricate. It contains at least 10.5 percent chromium. The higher the Chromium concentration in the steel, the more excellent the corrosion resistance. Stainless steel is ideal for food processing, medical instruments, hardware, appliances, and architectural products.

Features of Stainless Steel:

  • No corrosion, even when exposed to some acids.
  • Best for making machines that come into contact with food.
  • 100% recyclable.
  • We can reduce the thickness requirements of stainless steel due to its high strength.
  • Difficult to manufacture and easy to warp when welding.
  • Poor machinability.

Aluminum 

Aluminum is a silver-colored, low-weight, low-density, and smooth-looking metal. In most conditions, unalloyed aluminum is moderately strong, malleable, and highly resistant to corrosion. Aluminum is widely used in architectural, food, aerospace, transportation, and chemical handling (cookware, pressure vessels, etc.).

Features of Aluminum:

  • Lightweight material.
  • The oxide layer prevents rust and corrosion.
  • Easier to process and less expensive than copper.
  • Novice welders will have difficulty working on this metal.
  • CNC cutting technology is not as abundant as other metals.

Brass

Brass is an alloy of copper and zinc. It has desirable acoustic properties appropriate for use in musical instruments. Small amounts of zinc elements can be added to improve specific properties of brass. Alloying elements can increase hardness, strength, electrical and thermal conductivity, corrosion resistance, and color. Brass can be used for musical instruments, screws, firearm cartridge casing, pipes and tubing, radiators, architectural trim, and ornamental things.

Features of Brass:

  • Exhibits low friction.
  • A good conductor of heat.
  • Brass is easy to cast.
  • It has a relatively low melting point and high workability.
  • Brass has higher malleability than either bronze or zinc.
  • Brass resists corrosion, including galvanic corrosion from saltwater.
  • Brass is not ferromagnetic, making it easier to separate from other metals for recycling.

Copper 

Copper is a soft, malleable, and ductile metal with high thermal and electrical conductivity. A freshly exposed surface of pure copper is pinkish-orange in hue. Copper can be used as a building material, heat and electrical conductor, and component of different metal alloys. Copper alloys are excellent for electrical, transport, construction, and consumer goods industries.

Features of Copper:

  • Easily formed and inert to other metals.
  • A must-have for electronic part types.
  • It has high corrosion resistance.
  • High electrical and thermal conductivity.
  • It’s easier to bend and offers excellent aesthetics.

Sheet Metal Gauge Chart

We can use the gauge size charts to find the thickness of the sheet metal material. However, gauge thickness is dependent on the density of the material. Therefore, different materials use different gauge charts.

The table below describes the metal gauge chart for sheet steel, galvanized steel, stainless steel, aluminum, brass, and copper. Gauge is a measure of thickness; the smaller the gauge, the thicker the material.

Sheet Steel Gauge Chart

Sheet Steel Gauge Chart
ThicknessWeight Per Area
GaugeinmmIb/ft²kg/m²
30.23916.0739.75447.624
40.22425.6959.14644.656
50.20925.3148.53441.668
60.19434.9357.92738.701
70.17934.5547.31535.713
80.16444.1766.70732.745
90.14953.7976.09929.777
100.13453.4165.48726.79
110.11963.0384.87923.822
120.10462.6574.26720.834
130.08972.2783.65917.866
140.07471.8973.04714.879
150.06731.7092.74613.405
160.05981.5192.4411.911
170.05381.3672.19510.716
180.04781.2141.959.521
190.04181.0621.7058.326
200.03590.9121.4657.151
210.03290.8361.3426.553
220.02990.7591.225.955
230.02690.6831.0975.358
240.02390.6070.9754.76
250.02090.5310.8534.163
260.01790.4550.733.565
270.01640.4170.6693.267
280.01490.3780.6082.968
290.01350.3430.5512.689
300.0120.3050.492.39
310.01050.2670.4282.091
320.00970.2460.3961.932
330.0090.2290.3671.793
340.00820.2080.3351.633
350.00750.1910.3061.494
360.00670.170.2731.335
370.00640.1630.2611.275
380.0060.1520.2451.195

Galvanized Steel Gauge Chart

Galvanized Steel Gauge Chart
ThicknessWeight Per Area
Gaugeinmmlb/ft²kg/m²
80.16814.2706.85833.482
90.15323.8916.2530.514
100.13823.5105.63827.527
110.12333.1325.03024.559
120.10842.7534.42221.591
130.09342.3723.81018.603
140.07851.9943.20215.636
150.07101.8032.89614.142
160.063516132.5912.648
170.05751.4612.34611.453
180.05161.3112.10510.278
190.04561.1581.8609.083
200.03961.0061.6157.888
210.03660.9301.4937.290
220.03360.8531.3716.692
230.03060.7771.2486.095
240.02760.7011.1265.497
250.02470.6271.0084.920
260.02170.5510.8854.322
270.02020.5130.8244.023
280.01870.4750.7633.725
290.01720.4370.7023.426
300.01570.3990.6403.127
310.01420.3610.5792.828
320.01340.3400.5472.669

Stainless Steel Gauge Chart

Stainless Steel Gauge Chart
ThicknessWeight Per Area
Gaugeinmmlb/ft²kg/m²
00000000.500012.70020.808101.594
0000000.468611.90219.50195.213
000000.437511.11318.20788.894
00000.406310.32016.90982.555
0000.37509.52515.60676.195
000.34388.73314.30869.856
00.31257.93813.00563.496
10.28137.14511.70757.157
20.26566.74611.05353.966
30.25006.35010.40450.797
40.23445.9549.75547.627
50.21875.5559.10144.437
60.20315.1598.45241.267
70.18754.7637.80338.098
80.17194.3667.15434.928
90.15623.9676.50031.738
100.14063.5715.85128.568
110.12503.1755.20225.398
120.10942.7794.55322.229
130.09372.3803.89919.039
140.07811.9843.25015.869
150.07031.7862.92614.284
160.06251.5882.60112.699
170.05621.4272.33911.419
180.05001.2702.08110.159
190.04371.1101.8198.879
200.03750.9531.5617.620
210.03440.8741.4326.990
220.03120.7921.2986.339
230.02810.7141.1695.710
240.02500.6351.0405.080
250.02190.5560.9114.450
260.01870.4750.7783.800
270.01720.4370.7163.495
280.01560.3960.6493.170
290.01410.3580.5872.865
300.01250.3180.5202.540
310.01090.2770.4542.215
320.01020.2590.4242.073
330.00940.2390.3911.910
340.00860.2180.3581.747
350.00780.1980.3251.585
360.00700.1780.2911.422
370.00660.1680.2751.341
380.00620.1570.2581.260

Aluminum Gauge Chart

Aluminum Gauge Chart
ThicknessWeight Per Area
Gaugeinmmlb/ft²kg/m²
0000000.5814.7328.18539.962
00000 0.516513.1197.28935.587
00000.4611.6846.49231.694
0000.409610.4045.7828.222
000.36489.2665.14825.135
00.32498.2524.58522.386
10.28937.3484.08319.933
20.25766.5433.63517.749
30.22945.8273.23715.806
40.20435.1892.88314.076
50.18194.622.56712.533
60.1624.1152.28611.162
70.14433.6652.0369.942
80.12853.2641.8138.854
90.11442.9061.6147.882
100.10192.5881.4387.021
110.09072.3041.286.249
120.08082.0521.145.567
130.0721.8291.0164.961
140.06411.6280.9054.417
150.05711.450.8063.934
160.05081.290.7173.5
170.04531.1510.6393.121
180.04031.0240.5692.777
190.03590.9120.5072.474
200.0320.8130.4522.205
210.02850.7240.4021.964
220.02530.6430.3571.743
230.02260.5740.3191.557
240.02010.5110.2841.385
250.01790.4550.2531.233
260.01590.4040.2241.096
270.01420.3610.20.978
280.01260.320.1780.868
290.01130.2870.1590.779
300.010.2540.1410.689
310.00890.2260.1260.613
320.0080.2030.1130.551
330.00710.180.10.489
340.00630.160.0890.434
350.00560.1420.0790.386
360.0050.1270.0710.345
370.00450.1140.0640.31
380.0040.1020.0560.276
390.00350.0890.0490.241
400.00310.0790.0440.214

Brass Gauge Chart

Brass Gauge Chart
Thickness
Gaugeinmm
70.14433.665
80.12853.264
90.11442.906
100.10192.588
110.090742.305
120.080812.053
140.064081.628
160.050821.291
180.04031.024
200.031960.812
220.025350.644
240.02010.511
260.015940.405
280.012640.321
300.010030.255

Copper Gauge Chart

Copper Gauge Chart
Thickness
Gaugeinmm
70.184.572
80.1654.191
90.1483.759
100.1343.404
110.123.048
120.1092.769
140.0832.108
160.0651.651
180.0491.245
200.0350.889
220.0280.711
240.0220.559
260.0180.457
280.0140.356
300.0120.305

How to Choose the Right Sheet Metal Gauge for Your Project?

Using the correct sheet metal gauge is one of the technical skills a fabricator must possess. Incorrect sheet metal gauge can cost the end user dearly for such a mistake. Therefore, it is essential to use the proper sheet metal thickness to maximize efficiency and functionality. The following describes choosing the correct sheet metal fabrication gauge for your project.

Consider the Usage Scenario

Envisioning a usage scenario is the first step in choosing the correct sheet metal gauge for your project. Note that the lower the gauge, the thicker the metal, and the higher the gauge, the thinner the metal.

You should choose lower gauge sheet metal if you want a more rigid metal part like a stainless steel backsplash. This ensures that the metal part is strong and durable.

You should go for a higher gauge if your project needs something with different curves, such as a U-channel metal or a metal corner guard. Beyond that, the weather is a consideration, as it can also significantly impact the type of metal and gauge you select.

Consider Efficiency and Suitability

A project’s workflow from start to finish can be affected by the thickness of the sheet metal employed. A part made of sheet metal material of the correct thickness will perform the assigned task more efficiently. However, a part made with the wrong thickness of sheet metal material will not be able to perform its intended job effectively. As a result, considering efficiency and suitability will assist you in selecting the correct sheet metal gauge for fabrication.

Consider Cost

Cost is essential when selecting the proper gauge for sheet metal fabrication. Sheet metals made of thick materials are typically more expensive than their light materials counterpart. However, it would help if you first considered the metal’s intended purpose before considering its cost. This will help you select the correct gauge for your specific application.

Conclusion

Sheet metal thickness is denoted by gauge, sometimes spelled gage, which indicates a standard sheet metal thickness for a specific material. Sheet metal gauges can help you choose the right metal thickness for your project, ensuring metal durability, saving cost, and increasing efficiency. 

At LEADRP, our engineering and manufacturing team can suggest the appropriate sheet metal gauges for your project and provide excellent sheet metal fabrication processes. If you are looking for a company that offers cost-effective and on-demand metal fabrication, do not hesitate to contact LEADRP.

References

Sheet Metal Gauge– From Wikipedia

The story of the gauge – From Association of Anaesthetists

Sheet Metal Gauge Chart – From Metal Supermarkets

Sheet Metal Gauge Chart Guide And How to Customize Your Own Metal Part Online – From MC4U

Sheet Metal Gauge Size Chart – From CustomPartNet

FAQ

26 gauge steel is the industry standard for most light commercial and residential applications. 24 gauge steel is commonly used for standing seam panels and buildings subjected to high wind and snow loads.

Human judgment is prone to error, and even minor mistakes can have disastrous consequences for your construction. A sheet metal gauge is more accurate and comfortable to use.

No, you cannot do that. Ferrous and nonferrous metals come in different thicknesses and gauge wheels. If you use a single gauge wheel for ferrous and nonferrous metals, your measurements will not be accurate.

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