# Rectangular Steel Tube Sizes

The steel tube sizes commonly used for constructing steel tube buildings are rectangular in shape. Other than the columns being commonly of square steel tube or circular tubes, beams and girders are rectangular.

**For rectangular A36 tube pricing Click here or here for A36 square tube pricing.These links will prompt to select the tube size. For rectangular tubes the letters A & B represent the two sides, and C represents the thickness. For square tubes A represent the two sides and B thickness - all dimensions are inches, conversions to millimeters are also available. Once the tube size is selected a screen with pricing will appear. Please note these tube sizes are A36 steel, when using the design formula shown below to select the tube size needed, use Fy 36 ksi in lieu of 46 ksi, everything remain the same.

This page is about the rectangular tube steel available from structural steel manufacturer and structural steel suppliers in the United States. These steel structural tubing sections are industry standard that designers such as architects and engineers, fabricators, suppliers, home owners, and contractors all use.

Aesthetically, steel structural tubing is the most common type of steel for architecturally exposed building elements such as columns or beams.

Figure 32 provide the typical section properties of a rectangular tube steel. For HSS12x4x1/4 (12 inches high, 4 inches wide, 1/4 inch thick wall thickness. The first column W(lbs) stands for the weight in pounds per foot.

The next column A(in^2) stands for area of the steel measured in square inches. The next 4 columns are all properties used by engineers to determine the strength of each section.

When it comes to beam design, the section modulus S is the column commonly used. The sub-letters x and y shown refer to the strong and weak axis respectively.

The columns Sx and Sy act as guide for beam arrangements. Take for instance HSS12x4x1/4 Sx=19.9 in^3 with Sy=10.5 in^3. If you want to install the beam sideways with long side horizontal assuming the load applied will be vertically, then Sy should be used for sizing the beam.

For best floor beams performance though, the long side of the beam must be vertical and use the Sx to calculate the size to be used.