Steel Gauge Conversion Chart

A steel gauge conversion chart is a table that shows the various gauge thicknesses of different types of metal, including steel. The gauge thickness is a measure of the thickness of the metal, with a higher gauge number indicating a thinner material.

In the United States, the most commonly used gauge system for steel is the American Wire Gauge (AWG) system. However, other countries may use different gauge systems, such as the British Standard Wire Gauge (SWG) or the Standard Gauge (SG) system.

A steel gauge conversion chart will typically list the gauge number, the thickness in inches and millimeters, and the weight per square foot of the material. These charts can be useful for designers, fabricators, and manufacturers who need to select the appropriate thickness of steel for a particular application.

It is important to note that the gauge thickness alone does not provide a complete picture of the properties and performance of a particular type of steel. Other factors, such as the specific alloy, heat treatment, and manufacturing process, can also affect the strength, corrosion resistance, and other properties of the material.

A Steel Gauge Conversion Chart is your guide for the material thickness. While these gauge numbers do not indicate a specific dimensional value, they range between 3-30. Standard gauge sizes were developed based on the weight of the sheet for a given material and the equivalent thicknesses.

Gauge is derived from and related to the French word 'jauge', meaning 'result of measurement'. This form of measurement originated in the British iron wire industry when there was no universal unit for thickness. The sizes of the gauge numbers were the result of the process of wire-drawing and the nature of iron itself.

Gauges were measured and described in fractions of an inch during the 19th century. Artisans at the time found gauge sizes to be convenient, thus furthered its use. Moving into the 20th century, the gauge was to be replaced by the International System of Units, which ultimately did not occur.


  1. Steel Gauge Conversion Chart
  2. What are Gauge Sizes?
  3. What is the Gauge of a Tube?
  4. Pipe or Tube: What is the difference?
  5. What is Really Length?
  6. How is Weight Defined?
  7. What is Tensile Strength?

1. Steel Gauge Conversion Chart

The Standard Gauge Chart provides the thicknesses for Stainless Steel, Galvanized Steel, Sheet Steel and Aluminum. Gauge sizes are numbers that indicate the thickness range of a piece of metal, with a higher number referring to a thinner sheet. The equivalent thicknesses differ for each gauge size standard depending on the material.

Standard and metric conversion tables are commonly used in the Steel industry. Use the chart below to determine the equivalent thickness, in inches or millimeters, for a gauge number from the selected gauge size standard.

Steel Gauge Conversion Chart
Stainless Steel Galvanized Steel Sheet Steel Aluminum
Gauge Frac Inches mm Inches mm Inches mm Inches mm
30 0.0125 0.33 0.0157 0.40 0.0120 0.30 0.0100 0.25
29 0.0141 0.36 0.0172 0.44 0.0135 0.34 0.0113 0.29
28 1/64 0.0156 0.41 0.0187 0.47 0.0149 0.38 0.0126 0.32
27 0.0172 0.43 0.0202 0.51 0.0164 0.42 0.0142 0.36
26 0.0187 0.48 0.0217 0.55 0.0179 0.45 0.0159 0.40
25 0.0219 0.56 0.0247 0.63 0.0209 0.53 0.0179 0.46
24 0.025 0.64 0.0276 0.70 0.0239 0.61 0.0201 0.51
23 0 0281 0.71 0.0306 0.78 0.0269 0.68 0.0226 0.58
22 1/32 0.0312 0.79 0.0336 0.85 0.0299 0.76 0.0253 0.64
21 0 0344 0.86 0.0366 0.93 0.0329 0.84 0.0285 0.71
20 0.0375 0.95 0.0396 1.01 0.0359 0.91 0.0320 0.81
19 0.0437 1.10 0.0456 1.16 0.0418 1.06 0.0359 0.91
18 0.0500 1.27 0.0516 1.31 0 0478 1.21 0.0403 1.02
17 0.0562 1.40 0.0575 1.46 0.0538 1.37 0.0453 1.10
16 1/16 0.0625 1.59 0.0635 1.61 0.0598 1.52 0.0508 1.29
15 0.0703 1.80 0.0710 1.80 0.0673 1.71 0.0571 1.40
14 5/64 0.0781 1.98 0.0785 1.99 0.0747 1.90 0.0641 1.63
13 3/32 0.094 2.40 0.0934 2.37 0.0897 2.28 0.072 1.80
12 7/64 0.1094 2.78 0.1084 2.75 0.1046 2.66 0.0808 2.05
11 1/8 0.1250 3.18 0.1233 3.13 0.1196 3.04 0.0907 2.30
10 9/64 0.1406 3.57 0.1382 3.51 0.1345 3.42 0.1019 2.59
9 5/32 0.1563 3.97 0.1532 3.89 0.1495 3.80 0.1144 2.91
8 11/64 0.1719 4.37 0.1681 4.27 0.1644 4.18 0.1285 3.26
7 3/16 0.1875 4.76 0.1793 4.55 0.1443 3.67
6 13/64 0.2031 5.16 0.1943 4.94 0.162 4.10
5 7/32 0.2187 5.55 0.2092 5.31 0.1819 4.62
4 15/64 0.2344 5.95 0.2242 5.69 0.2043 5.19
3 1/4 0.25 6.35 0.2391 6.07 0.2294 5.83

2. What are Gauge Sizes?

Gauge sizes refer to the measurement of the thickness of a material, typically metal or wire. The gauge size is a numerical value that represents the thickness of the material, with a higher gauge number indicating a thinner material.

In the United States, the most commonly used gauge system is the American Wire Gauge (AWG) system, which is used to measure the thickness of electrical wire. In this system, the gauge sizes range from 0000 (four zeros) to 40, with 0000 being the thickest wire and 40 being the thinnest.

For sheet metal and other flat materials, gauge sizes are typically expressed in a range of numbers, such as 18 gauge to 30 gauge. The thickness of the material will depend on the specific gauge number, with a lower number indicating a thicker material.

It is important to note that the actual thickness of a material can vary depending on the specific alloy, manufacturing process, and other factors. Therefore, it is always important to check the actual thickness of a material rather than relying solely on the gauge size.

3. What is the Gauge of a Tube?

The gauge of a tube refers to the thickness of the wall of the tube. Tube gauges are typically expressed using a number followed by the letters "SWG," which stands for "standard wire gauge." For example, a tube with a 16 SWG thickness has a wall thickness of 0.065 inches (1.65 millimeters).

Tube gauges can vary depending on the specific material and application. For example, tubes made of stainless steel, aluminum, or copper may have different gauge sizes than tubes made of carbon steel. Additionally, tubes used in high-pressure applications may have thicker walls to withstand the pressure.

It is important to note that the inside diameter (ID) of a tube can also vary depending on the thickness of the wall. Therefore, it is important to consider both the gauge and the ID when selecting a tube for a particular application.

4. Pipe or Tube: What is the difference?

Pipes and tubes are both used for the transportation of fluids or gases, but there are some differences between them.

The main difference between pipes and tubes is in their composition and how they are made. Pipes are generally made from carbon steel, stainless steel, or galvanized steel, and are designed to carry liquids or gases under pressure. They are typically measured by their inside diameter (ID) and wall thickness, and are often used in industrial applications such as oil and gas pipelines, water treatment plants, and chemical processing facilities.

Tubes, on the other hand, can be made from a variety of materials including carbon steel, stainless steel, aluminum, brass, and copper. They are typically measured by their outside diameter (OD) and wall thickness, and are often used in applications such as structural supports, heat exchangers, and hydraulic systems.

Another key difference between pipes and tubes is in their manufacturing process. Pipes are generally made by rolling steel sheets into a cylinder and welding the seam, while tubes can be made by several different processes, including extrusion, welding, and seamless drawing.

In summary, while pipes and tubes may have some similarities in terms of their usage, composition, and manufacturing processes, they differ in their measurement, purpose, and how they are made.

5. What is Really Length?

Length is a physical quantity that refers to the measure of distance between two points. It is typically measured in units such as meters, centimeters, feet, or inches. The concept of length is fundamental to many areas of science and engineering, including physics, mathematics, and architecture, among others. In physics, for example, the distance between two objects is an important factor in determining the force of gravity between them, while in architecture, the length of a room or building is crucial for determining its layout and functionality.

Length is a measure of distance as defined in the International System of Quantities (ISQ). This term is often used in physics and modern science. The use of basic quantities such as length and mass, and the relationships between those quantities are common. This relationship underlies the International System of Units but doesn't determine the units of measurement used for the quantities.

Various terms for the length include height, width and depth. Height is used when there is a base from which a vertical measurements can be taken. Width usually refers to a shorter dimension and Depth is used for the third dimension of a three dimensional object.

This chart shows the relationship between standard and metric system of measurement is standard across all industry.

Meter Millimeter Inch Feet Yard
m mm in
ft yd
1 1000 39.3700 3.2808 1.093613
0.001 1 0.03937 0.00328 0.001093
0.0254 25.4 1 0.08333 0.08777
0.3048 304.8 12 1 0.333
0.9144 914.4 36 3 1

6. How is Weight Defined?

Weight is the measure of the force exerted on an object due to gravity. It is a vector quantity, meaning that it has both magnitude and direction. The weight of an object depends on its mass and the strength of the gravitational field it is in.

In simpler terms, weight is the force with which an object is pulled towards the center of the Earth by the gravitational attraction between the object and the Earth. The weight of an object can be measured in units such as pounds or kilograms using a scale or a balance.

It is important to note that weight is different from mass. Mass is a measure of the amount of matter in an object, while weight is the force exerted on an object due to gravity. Mass is typically measured in units such as grams or kilograms, while weight is measured in units such as pounds or newtons.

The weight of an object is the force acting on the object due to gravity as defined in the science and engineering community. While weight and mass are scientifically distinct quantities there terms are often mixed with each other in everyday use. Weight per unit area can also be seen in pounds per square foot or kilograms per square meter.

The unit of measurement for weight is force. In the International System of Units (SI) it is the newton. In the metric system of measurement weight is defined as Kilogram-force which is the force exerted by Earth's gravity at sea level on one kilogram of mass. Pound of force or pound-force in English Engineering units. Pound-Force is defined as gravitational force applied on a mass of one pound at sea level.

Building safety specifications are commonly defined in kilonewtons. This includes the holding values of fasteners, Earth anchors, Railing loads and other items used in the building industry as well as working loads in tension and in shear. The chart below show the relation between common units used in industry.

Kilogram Ton Pound
Kg Ton Lb
1 0.001 2.2045
1000 1 2204
0.4536 0.000453 1

7. What is Tensile Strength?

Tensile strength is a measure of the maximum stress that a material can withstand before breaking or fracturing under tension. It is the ability of a material to resist being pulled apart by opposing forces, such as stretching or elongation.

Tensile strength is an important mechanical property of materials, especially in engineering and construction, as it helps to determine the suitability of a material for a particular application. The tensile strength of a material is typically expressed in units of force per unit of cross-sectional area, such as newtons per square meter (N/m²) or pounds per square inch (psi).

The tensile strength of a material is influenced by various factors, including its chemical composition, microstructure, and processing history. Different materials have different tensile strengths, with some materials being much stronger than others. For example, steel is known for its high tensile strength, while materials like rubber or plastic have much lower tensile strengths.

The maximum stress a material can withstand while being stretched or pulled before breaking is referred to as tensile strength. This is not dependent in size of the material. Tensile strength of the material is used in the engineering calculations in the construction industry.

Factors such as material preparation, surface defects and the environment do effect tensile strength. Quality in the manufacturing process is important in minimizing these effects.

The strength per square inch or Tensile Strength is shown in KSI, PSI, and Megapascal units.

Pound/Square Inch 1000 Pound/Square Inch Megapascal
1 0.001 0.006895
1000 1 6.895
145.0326 0.1450326 1