What is Sheet Metal Gauge Chart?

Introduction

In many quotation requirements for metal sheets, we often find words such as “16 gauge stainless steel sheet”. People who don’t know the gauge system will be clueless when they see such terms for the first time. In this article, HYT will explain the meaning of the metal sheet gauge system, how to use it, and the gauge charts of common metal sheets.

What is Gauge System?

The Gauges system is mainly a standardized system used to indicate the thickness of metal sheets. Sheet metal gauge is generally used to describe the thickness of metal sheets. Therefore, this specification can not only be used to express the thickness of steel sheets, but also the thickness of aluminum sheets, galvanized sheets, copper sheets, etc. However, there are two points we must pay attention to.

First, gauge is not a standard unit of measurement and does not belong to the metric or imperial measurement system. The number in front of the gauge does not reflect the actual metal sheet thickness data, but reflects the thickness of the required sheet in the gauge system chart of a specific material. Therefore, the number in front of the gauge is more like the serial number corresponding to each thickness in the gauge chart.

Therefore, when we encounter a gauge system conversion table for the material “16 gauge stainless steel sheet”, we should first find the equivalent imperial and metric values ​​corresponding to the serial number 16. For example, the thickness of “16 gauge stainless steel sheet” in the gauge chart of the material stainless steel is 1.587mm (metric) and 0.0625 inches (imperial).

Secondly, we must remember that the gauge systems of different materials are completely different, and we must choose the corresponding gauge conversion table according to the specific material. For example, if the material is stainless steel, the thickness of the stainless steel sheet is 0.0625 inches or 1.587mm; if the material is aluminum, the thickness of the aluminum sheet is 0.05082 inches or 1.291 mm. We found that the thickness of the aluminum sheet is completely different from that of the stainless steel sheet after conversion according to the gauge conversion table of stainless steel and aluminum, which is also 16 gauge.

Generally speaking, the larger the number in front of the gauge in the gauge size chart, the thinner the thickness of the metal sheet. However, if the material is zinc, on the contrary, the larger the number in front of the gauge, the thicker the sheet.

Common Types of Sheet Metal Gauges Standards

Not all metals use the same gauge standards. The following are common gauge systems:

Where Does the Gauge System Come From?

The gauge system was not originally used to indicate the thickness of metal sheets. It originated from the production process of metal wire. During the Industrial Revolution in the 18th century, craftsmen in the wire industry mainly relied on the drawing process to produce metal wire. Specifically, this process is to pull a piece of metal blank through a gradually shrinking die hole to make its diameter smaller and smaller, so that a thinner metal wire is obtained. The value of the gauge of a metal wire indicates the number of wire drawing in the production process. After each wire drawing, the diameter of the metal wire becomes thinner.

Therefore, the larger the number before the gauge, the thinner the wire. Therefore, a 20 gauge metal wire is thinner than a 10 gauge metal wire. At that time, the total price of metal wire was mainly calculated based on weight, but some buyers found that after receiving the goods, some metal wires were thicker and some were thinner, which caused great trouble to buyers. In order to standardize the thickness of metal wire, the metal wire gauge standard was adopted.

With the advancement of the Industrial Revolution, the demand for metal sheets in many important industries has also increased significantly. When people use metal sheets, they also need a standardized thickness identification system similar to wires. Therefore, the gauge system was introduced into the metal sheet field. Although metal sheets do not use the drawing process for production, the hot rolling, cold rolling and other rolling processes used can thin the metal sheets. The more times the rolling process is, the thinner the sheet metal is. Therefore, similarly, in the sheet metal gauge standard, the larger the number in front of the gauge, the thinner the metal sheet is.

Why Do We Still Use Gauge Standard?

Although we use metric or imperial units as standard measurement methods in current international trade, the gauge system still plays an important role in many industries. This is mainly because the gauge system has the following values:

1. Intuitiveness

In the metal manufacturing and processing industry, skilled technical workers can quickly determine the thickness of the material based on the gauge number. In many industries, workers are more familiar with steel plates with gauge thickness numbers rather than steel plates with a specific metric or imperial value thickness;

2. Convenient for Quick Weight Estimation

The gauge system is equivalent to a predefined table, which contains not only the material thickness value but also the weight value per unit area. Workers only need to find the material thickness according to the number in front of the gauge and the gauge system conversion table of the corresponding material, and then they can immediately find the corresponding unit area weight.

Let’s take 16 gauge steel sheet as an example. In the standard steel gauge system, we can immediately find the metric and imperial thickness data corresponding to 16 gauge steel sheet, as well as the corresponding unit weight value.

16 gauge = 0.060″ = 1.519mm

Weight Per Area = 2.440lb/ft² = 11.911 kg/m²

Now that we have the unit weight of a 16 gauge steel sheet, we can quickly calculate the total weight based on the area.

If we use metric or imperial units, we need to know the thickness, density, and area of ​​the metal product to calculate the total weight of this batch of metal sheets.

Therefore, from the perspective of calculating weight, the gauge system is faster and more efficient than the metric or imperial system;

3. Industry Inertia

The gauge system has been used as a thickness identification standard for hundreds of years, and many modern standards and supply chain cargo management still use the gauge system. Although metric and imperial units are the mainstream in current international trade, it will take a long time for the gauge system to be completely replaced.

Sheet Metal Gauge Charts

Standard Steel

Galvanized Steel

Stainless Steel

Mild Steel

Aluminum

Zinc

Brass

Copper

Birmingham Gage