Pipe and Tube Specifications

The three most common industrial tubing sizes are 1", 1.5", and 2" OD, used for conveyor frames, equipment supports, and architectural railings. In stainless square tube, these dimensions are measured outside face-to-face.

Stainless steel square tube is measured by its outside dimension (OD) across each face. A 2" x 2" square tube has a 2" outside face-to-face measurement. The wall thickness determines the inside dimension.

Nesting fit depends on wall thickness. For example, a 1-1/2" OD square tube typically fits inside a 2" OD tube with a standard 0.065" wall (leaving approximately 0.187" clearance per side). Verify exact fits with dimensional specifications from Stainless Shapes.

12-gauge stainless steel square tube has a wall thickness of approximately 0.1046 inches (2.66mm). This is a common medium-weight specification for structural tube applications in food processing equipment and architectural frameworks.

Stainless steel square tube is commonly referred to as square hollow section (SHS) or square structural tubing. In the metals industry it is called square tube or square mechanical tubing to distinguish it from solid square bar.

14-gauge stainless steel square tubing has a wall thickness of approximately 0.0747 inches (1.90mm). This is a common gauge for lighter structural and architectural applications such as railings, equipment frames, and enclosures.

Square tubing is available in gauges from 22 (lightest) through 7 (heaviest), plus 3/16" and 1/4" wall thicknesses for heavier structural use. The most commonly stocked stainless gauges are 16, 14, 12, 11, and 10 gauge.

For bending loads in one plane, a rectangular tube oriented with the longer dimension resisting bending is stronger than a square tube of equal weight. For equal performance in multiple directions, square tube is preferred. For torsional loads, square tube outperforms rectangular.

3-1/2" square tubing is considered non-standard. Standard sizes typically jump from 3" to 4". If 3-1/2" x 3-1/2" is required, contact Stainless Shapes to check availability or arrange a special order.