Metal Enclosure Design Tips | Metal Thickness

What’s the worst case scenario for an engineer designing a metal enclosure or cabinet? It’s the structural integrity failing. The metal thickness used in an enclosure directly impacts its structural integrity, and poor structural integrity can compromise your design.

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If you’re unsure what metal thickness to use for your product, we're here to help! After reading this, you will gain a better understanding of metal thicknesses, how they differ between metal types, how to measure different metals, and how to choose a gauge/thickness for your project. For quick reference, we’ve created a downloadable desk guide for metal gauges.

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Why does metal thickness matter for enclosure fabrication?

As mentioned above, selecting the proper metal thickness is vital to a successful design. It’s the difference between a product lasting and failing during transportation, installation, or while deployed in the field. Incorrect material thickness can have significant consequences, ranging from minor to catastrophic. For instance, an unnecessarily thick piece of metal can add too much weight to an enclosure. This additional weight makes it difficult to transport and install the product and can result in product failure in the field. Imagine a tall kiosk installed in a public domain; for safety reasons, you wouldn’t want it tipping over onto a customer or user.

Conversely, consider a utility cabinet. A company may request a thinner gauge panel for the door to make it easier to open. However, if the gauge is too thin, the metal can warp and bend from the repeated motion of opening and closing the door. This warping means that the door will likely need replacement across multiple units, resulting in higher material costs, rework, and additional maintenance hours.

Gauges or Inches? How do you measure metal thickness?

Certain metal types are measured differently in terms of thickness. For ferrous metals, like stainless steel and galvanized steel, thickness is measured in gauges. Common gauges range from 14 gauge to 24 gauge for galvanized steel, and 8 gauge to 22 gauge for stainless steel. The higher the gauge, the thinner the metal. For example, a 14 gauge sheet of stainless steel is thicker than a 20 gauge sheet. Many sheet metal manufacturers utilize 8 gauge steel or thinner. If you get thicker steel than that, it is no longer referred to as sheet metal, but as plate metal.

The thickness of aluminum and other non-ferrous materials is measured in inches. Common aluminum thickness can vary between .030” and .186”. Metal thickness is often discussed and written about in conjunction with tolerances and nominal sizing. For example, a 16 gauge sheet of stainless steel has a nominal size of .057” with a tolerance of +.006/-.000. Since aluminum is non-ferrous and not measured in gauges, its thickness would be described as .061 ± .002. So how do you choose the right metal thickness for your product?

Choosing the right material thickness for your metal product

Engineers typically decide gauge or thickness on a case-by-case basis. The best place to start is by assessing your product needs and evaluating material type, weight and strength requirements, and allowable flex. Next, discuss your program needs, including installation sites, climate, transportation requirements, and other variables. With these questions answered, you can select the gauge/thickness that best reflects those specifications and needs. Other factors, such as cost and availability, may also influence the selection process, but this is a great starting point.

Here’s another quick tip: If thinner sheet metal is necessary due to weight or other requirements, consider adding stiffeners or form features. These are commonly added to sheet metal enclosures to maintain structural integrity.

How can you keep track of it all? We’ve created a handy desk guide for quick reference during the design process that includes common sheet metal thicknesses and tolerances. While there are additional gauges and thicknesses available for metals, we have only included the most standard options to avoid those that typically take longer to custom order and cost more.

DOWNLOAD THE GUIDE HERE

For more information, please visit AJR.

Wrapping it up

This month's enclosure design tips reviewed how to measure the thickness of various metals, and why it’s crucial to choose the proper thickness for your sheet metal product. Choosing the right metal gauge/thickness for your project is only one step in the design process. Are you looking for additional metal fabrication design tips? Learn how you can apply design for manufacturing (DFM) principles to speed up production and cut costs. See how! Are you looking for a fabrication partner for your metal enclosures, kiosks, or cabinets? Talk to our team: https://www.maysteel.com/contact/.

©2020 Maysteel Industries, LLC

Metal gauge thickness (aka gage thickness) dates back to the 1800s, before a unit of measure for thickness was universally agreed upon. It is a way of measuring the thickness of material via density. The processes of manufacturing at the time the gauge system was developed were crude by today’s standards, so material thickness was very inconsistent by comparison. Measuring by the weight of the sheet metal was more representative of the average thickness than any one thickness measurement was likely to be (it was also easier).

Gauge Thickness vs Measured Thickness

Sheet metal gauge thickness is another way to describe the actual thickness. Think of gauge thickness vs measured thickness as being similar to the difference between metric and imperial units. Both gauge thickness and measured thickness convey a standardized measurement describing sheet metal, but just with different numbers and bases of measurement.

With metric, the base measurement is 10, i.e. 10 mm = 1 cm. For gauge thickness, the base is the number of drawing operations. This base is less consistent, as the change in thickness from 3 gauge stainless to 4 gauge is 0.016” vs from 24 to 25 gauge stainless it is only 0.003”. This is due to material properties that limited how much reduction could take place with a single drawing operation. This is also why each material has a unique gauge conversion chart due to variations in material properties. Below is an example sheet metal gauge chart for stainless steel.

30.2506.3540.2345.9450.2195.5660.2035.1670.1884.7680.1724.3790.1563.97100.1413.57110.1253.18120.1092.78130.0942.39140.0781.98150.0701.78160.0631.59170.0561.42180.0501.27190.0441.12200.0380.95210.0340.86220.0310.79230.0280.71240.0250.64250.0220.56260.0190.48280.0160.41

A potential challenge with gauge thickness measurement is that different materials use different gauge charts. For example, stainless steel uses a stainless steel gauge chart, while aluminum will only use an aluminum gauge chart. Since you have to use and keep track of different gauge charts, it’s easy to mistakenly order the wrong thickness of material.

Here’s an example of how material thickness can vary:

• If you order 10 gauge stainless steel, you’re going to get a physical measurement of 0.135.”
• If you order 10 gauge aluminum, you’re going to get a physical measurement of 0.102.”

That’s a 0.033” difference, which is well outside the tolerances for most designs. Using the wrong gauge chart can be a big detriment to your design.

Types of Sheet Metal Gauge Charts

A gauge chart is a table that matches a material’s gauge to the decimal equivalent thickness. Some gauge charts will also include thickness tolerance and/or a measurement in multiple units. It is important to know the difference between gauge thickness and dimensional thickness as well as how to read a gauge chart because some industries and some metal suppliers still use the gauge system to specify sheet metal thickness (we like to make it easier on you, and directly provide an actual thickness in both inches and metric when you order). Additionally, note that as the gauge number goes higher, the thickness decreases. This ties back to the origins of the gauge measurement system in the metal wire production industry, where gauge number was measured by the number of drawing operations needed to achieve a certain wire size. Due to differences in material properties, conversion from gauge number to actual thickness is unique for each material, so always use the appropriate chart!

The charts below match the decimal equivalent thickness of each material to the equivalent gauge measurement in both imperial and metric units. As a reminder, the thickness decreases as the gauge number increases. To use a sheet metal gauge chart, select the chart matching the desired material, then find the row corresponding to the desired thickness; the left column will indicate the correct gauge for that thickness.

Mild/Carbon Steel Gauge Chart

30.2396.0740.2245.6950.2095.3160.1944.9470.1794.5580.1644.1890.1503.8100.1353.42110.1203.04120.1052.66130.0902.28140.0751.9150.0671.71160.0601.52170.0541.37180.0481.21190.0421.06200.0360.91210.0330.84220.0300.76230.0270.68240.0240.61250.0210.53260.0180.45280.0150.38

Galvanized Steel Gauge Chart

80.1684.2790.1533.89100.1383.51110.1233.13120.1082.75130.0932.37140.0791.99150.0711.8160.0641.61170.0581.46180.0521.31190.0461.16200.0401.01210.0340.93220.0340.85230.0310.78240.0280.7250.0250.63260.0220.55280.0190.47

Stainless Steel Gauge Chart

30.2506.3540.2345.9450.2195.5660.2035.1670.1884.7680.1724.3790.1563.97100.1413.57110.1253.18120.1092.78130.0942.39140.0781.98150.0701.78160.0631.59170.0561.42180.0501.27190.0441.12200.0380.95210.0340.86220.0310.79230.0280.71240.0250.64250.0220.56260.0190.48280.0160.41

Aluminum Gauge Chart

30.2295.83 40.2045.1950.1824.6260.1624.1170.1443.6780.1293.2690.1142.91100.1022.59110.0912.30120.0812.05130.0721.83140.0641.63150.0571.45160.0511.29170.0451.14180.0401.02190.0360.91200.0320.81210.0280.71220.0250.64230.0230.58240.0200.51250.0180.46260.0170.43280.0130.32

Sheet Metal Gauge: 4 Tips to Make the Right Selection for Your Project

Below are outlined four things to keep in mind when selecting materials and/or gauge thickness for your next project. For more in-depth material selection guidance, check out our article here: Material Selection Guide.

Consider Material Properties

What is driving your material selection, and what material best meets your design requirements? For example, a stronger material might allow for a thinner gauge of metal.

• Consider:
  • Material strength
  • Density
  • Corrosion resistance
  • Cost
  • Malleability
  • Conductivity
  • etc.

Choose a Process

The type of process being done on the metal can change material selections.

• Bending – Consider reading our guide: Design Considerations When Planning Sheet Metal Bends
  • Some metals are more malleable and bend better
  • Some metals have a max or minimum material thickness for bends
• Welding
  • Some metals weld better than others (i.e. mild steel is easier to weld than stainless steel)
  • Some metals have a max or minimum material thickness for welds
  • Is your material reliant on heat treatment for proper performance?
    • Welding removes heat treatments in the welded region

Define the Necessary Thickness

• Take into account the thickness required for a part
  • Does it need to support a certain weight?
  • Can it flex or does it need to be very stiff?
  • Does it have a maximum weight?

Reduce Production and Shipping Costs

• Thicker materials drive up the cost of both production and shipping
  • Choose the thinnest material that meets the required thickness to minimize cost

Video Guide to Understanding Gauge Thickness

Watch the video and follow along with the transcript below to learn the difference between gauge thickness and actual thickness, and how SendCutSend is making it easier for you to pick what’s best for your project.

Material Selection: How SendCutSend Makes it Easier For You

Utilizing the proper material thickness is crucial for ensuring parts work safely, are efficient with weight, and keep costs down. To protect your design and help prevent you from ordering the wrong material thickness, we made it easy with our material selection guide. You’ll see all the physical measurements that we have for that material in both imperial (inches) and metric (millimeters) units. Choosing your thickness based on actual physical measurements will help prevent costly mistakes that could occur when ordering parts based only on gauge thickness.

If you have any questions, feel free to reach out to our support team. When you’re ready, upload your design and get instant pricing today!

If you are new to SendCutSend, here’s a handy step-by-step guide on how to order parts from us: How to Order Parts from SendCutSend (spoiler alert: it’s super simple and intuitive to order from us).

FAQ

18 gauge metal is thicker. This ties back to the wire making origins of the gauge measurement system, where the number corresponds to the number of times the wire size was reduced, so reducing the wire size 20 times results in a smaller diameter than 18 times.

Sheet metal gauge refers to the thickness of sheet metal. It is unique to the type of metal, i.e. 10 gauge stainless steel is not the same thickness as 10 gauge aluminum.

14 gauge metal is thicker. This ties back to the wire making origins of the gauge measurement system, where the number corresponds to the number of times the wire size was reduced, so reducing the wire size 16 times results in a smaller diameter than 14 times.