Sheet metal thickness directly affects product quality, durability, and costs.
Choosing the wrong thickness can lead to material failures (too thin) or overengineering (too thick), resulting in excess costs, weight and more. In this guide, we walk you through the basics of selecting the right sheet metal thickness for your projects.
What is sheet metal thickness?
Sheet metal is under ¼ (0.25”) thick. Anything thicker is called a plate.
In North America, we measure it in two ways:
- Gauges (like 14 gauge) – industry standards
- Inches (like 0.0747″) – precise measurements
While Europe and Asia primarily use the metric system, thus millimeters (mm).
Understanding sheet metal gauges
The gauge system works in reverse. The higher the gauge number, the thinner the metal.
For example, for cold-rolled steel (CRS), 20 gauge (0.0359″) is much thinner than 14 gauge (0.0747″). While this might seem counterintuitive, it is the standard in the industry.
Gauge thicknesses vary by metals
Different metals have different thicknesses for the same gauge number. For instance, 14-gauge steel (0.0747″) is thicker than 14-gauge aluminum (0.0641″). To avoid confusion, always specify the gauge number and the type of metal.
CRS sheet metal thickness chart
Gauge | Inches* | Applications | Materials |
---|---|---|---|
7 | 0.1793 | Heavy structural components | Hot-rolled steel |
10 | 0.1345 | Machine guards, heavy brackets | Cold-rolled steel, stainless steel |
12 | 0.1046 | Sturdy enclosures, frames | Steel, stainless steel |
14 | 0.0747 | Medium-duty brackets, panels | Steel, aluminum, stainless steel |
16 | 0.0598 | Light fixtures, cabinets | Steel, aluminum |
18 | 0.0478 | HVAC components, boxes | Galvanized steel, aluminum |
20 | 0.0359 | IC boxes, electronic enclosures | Cold-rolled steel, aluminum |
22 | 0.0299 | Light-duty enclosures | Galvanized steel |
24 | 0.0239 | Ductwork, flashing | Galvanized steel, aluminum |
26 | 0.0179 | Computer cases, light covers | Various |
28 | 0.0149 | Electronics shielding | Various |
30 | 0.0120 | Decorative elements | Various |
*Nominal thickness; the same gauge number in different metals = different thicknesses.
Material thickness tolerances
Every material has its own inherent thickness tolerances. Failing to account for these subtle differences can lead to inaccuracies in your product designs or assemblies.
For example, 14 GA steel (0.0747″), the actual thickness can vary by ±0.007″ in standard production. This means your material could range from 0.0677″ to 0.0817″ thick. Here’s how much tolerance variations to expect based on various materials and thicknesses.
Sheet metal tolerance table
Fabrication tolerances
When parts are manufactured, additional tolerances come into play based on fabrication processes:
- Forming and bending: ±0.010″ to ±0.030″ depending on complexity
- Hole locations: ±0.005″ to ±0.015″ typical
- Overall part dimensions: ±0.015″ to ±0.060″ based on size
- Feature-to-feature: ±0.010″ to ±0.030″ typical
These tolerances are general guidelines and vary based on part design, tooling, and manufacturing method. Always discuss specific tolerance requirements with your manufacturer during the design phase.
How to select the right thickness
When picking a thickness, consider:
- What material is required or are you considering?
- How strong does it need to be?
- Does it need to be bent or shaped? (Thinner material is easier to shape.)
- What’s your budget for each part? (Thicker metals typically cost more.)
Sheet metal thickness standards
Most sheet metal fabrication projects fall into these ranges:
- 10-14 gauge: Heavy-duty structural parts
- 16-20 gauge: General industrial & commercial parts
- 22-26 gauge: Light-duty and residential applications
Common applications by thickness
Very thin (26-30 gauge)
- Ductwork
- Flashing
- Simple brackets
- Computer enclosures
- Electronics shielding
Medium (16-24 gauge)
- Light fixtures
- Junction boxes
- Electronic enclosures
- HVAC components
- Driver boxes
Thick (10-14 gauge)
- Heavy-duty brackets
- Structural components
- Machine guards
- Support frames
Money-saving tips
- Don’t use thicker metal than you need.
- Stick to standard gauges (even-numbered) or thicknesses where possible.
- Consider using ribbing or bends to add strength instead of using thicker metal.
- Talk to a manufacturer about the most cost-effective thickness for your project.
Bottom line
Picking the right material thickness is crucial for your project’s success. Choose the wrong material or thickness, and your product may fail. Too thick, and you risk overspending on parts. When in doubt consult with your metal fabricator for material and thickness recommendations.