Steel Pipes & Tubing, Cebu
Square and Rectangular Tube
Square and rectangular tube, commonly called tubular, is hollow steel section used for framing. The closed shape resists twisting and bending far better than an open section of the same weight, which is why it is the default for gates, railings, canopies, and light structural frames.
Specification
Sizes and variants
Square tube, black iron (BI)
Uncoated. The usual choice where the frame will be painted or is under cover.
From 3/4 x 3/4 upward, in wall thicknesses from 1.0mm
Square tube, galvanized iron (GI)
Zinc-coated for better corrosion resistance in exposed or humid conditions.
Same sections as black iron, in wall thicknesses from 1.0mm
Rectangular tube
Where a section needs more depth in one direction than the other.
1 x 2, 1 x 3, 2 x 3 and larger, in black iron and galvanized
- Finish
- Black iron (BI) or galvanized iron (GI)
- Wall thickness
- From 1.0mm, in steps up to 2.0mm and above
- Measured by
- Section size in inches, wall thickness in millimetres
Availability varies by size. Other sizes can often be sourced on request.
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Applications
Where it is used
- Gates, grilles, and railings
- Canopies and light structural frames
- Furniture and fabrication
- Signage and support frames
Questions
About square and rectangular tube
What is the difference between BI and GI tube?
Black iron is uncoated steel. Galvanized iron has a zinc coating that resists corrosion, so it lasts longer where it is exposed to weather or humidity. Black iron is normally chosen where the frame will be painted or kept under cover, and galvanized where it will not.
How is tubular sized?
By its outside section in inches and its wall thickness in millimetres. A 2 x 3 tube with a 1.2mm wall and the same tube with a 2.0mm wall are very different in strength and weight, so both figures matter when ordering.
Which wall thickness do I need?
Thinner walls suit light frames, furniture, and signage. Thicker walls are for anything carrying structural load or spanning a distance. If the drawing specifies a thickness, follow it rather than substituting a lighter section.
Looking for other sizes or grades? See the full Steel Pipes & Tubing range.
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