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Square Structural Steel Tubing

Structural steel tubing is designed to provide strength and rigidity to structures while minimizing weight. Square tubing has a square cross-section, which makes it suitable for use in applications where rectangular shapes are needed, such as the construction of frames, supports, and other structures. It is often used to create complex structures or shapes. 

Lock Joint Tube has created a variety of square structural & mechanical steel tubing in the following shapes:

  • Square Tubing with Sharp Corners
  • Square Tubing with Large Corners

We carry steel tubing in rectangleround, oval, non-symmetrical & specialty shapes. All tubes are produced to ASTM 513 if uncoated or 787 if it is coated. LJT is also able to meet customized requirements and specialty projects.


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Several sizes of square steel tubing offered by Lock Joint Tube.

Square Steel Tubing Capabilities

Square tubing is available in a variety of sizes, thicknesses, and materials, making it versatile and suitable for a wide range of applications.

Outside Diameter: 0.375” – 6.0”

Wall Thickness: 0.03” – 0.375”

Material Types:



Square structural steel tubing is commonly used in construction and manufacturing industries. Its square shape makes it ideal for building frames, supports, and other structures that require strength and stability. Some of the specific uses of square structural steel tubing include:

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Square Tubing Specifications

  • ASTM A513
  • ASTM A500
  • ASTM A1011
  • ASTM A1008
  • ASTM A787
  • JIS G3445
  • SAE J1392
  • SAE J2340
  • European Equivalents /EU equivalents of above


Specifications in Alloy:

  • 4140 Square Steel Tubing 
  • 4130 Square Steel Tubing

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Give us a call at 800-257-6859 or leave us a message.

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