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High-Strength Galvanized Steel Tubing for Residential & Commercial Construction

Review Allied’s product catalog for their galvanized steel tubing. This includes detailed information about their signature Flo-Coat process, fabrication options, performance, and benefits like its superior corrosion protection.

The Flo-Coat®Process

Allied’s zinc Flo-Coat galvanized steel tubing is the product of choice for residential and commercial construction. The unique, in-line Flo-Coat process provides a triple layer of corrosion protection that stands the test of time. The process begins with flat strip steel, which is cold formed and electric-resistance or induction welded. The cold forming and quenching process creates greater yield and tensile strength compared to alternative tubing of the same O.D. and gauge. After welding, the tube goes through three coating baths. The first coating bath bonds zinc to the hot tubing, and is followed by a conversion coating bath. The process chemically changes the zinc already on the surface of the tube. The compounds which are formed make the zinc even less subject to corrosion than unprotected zinc. This conversion coating also provides another layer of protection for longer resistance to white rust corrosion. The excess solution is then removed from the tube and the tube is dried to prepare for its third and final protective coating bath…an application of a clear organic polymer to give the tube superior corrosion resistance, added aesthetic appeal, and long-lasting surface brightness. This coating is then cured to a smooth, hard finish near the end of the in-line process. The result is a smooth, shiny end product appearance that is unmatched in terms of strength and durability – it will not oxidize or “gray down” with age, nor will the coating flake off during fabrication operations.

More than Double the Performance vs. PreGalvanized Tube

Allied’s Flo-Coat galvanized steel tubing provides outstanding corrosion protection because of the synergism created between the three coatings. The conversion coating passivates the zinc to slow down the white rust growth process, and the clear topcoat then “seals in” the protection. Pregalvanized products do not provide this “sealed” protection. On the inside of Allied’s Flo-Coat galvanized steel tubing a corrosion-resistant zinc based coating is applied after the tube is welded, and completely covers the interior. When pregalvanized steel is formed and welded, the inside weld area is left bare – unprotected since the interior cannot be re-metalized. The exposed metal is immediately left to be attacked by all corrosive elements. The exterior of the weld is re-metalized, but is still far more susceptible to corrosion than Allied’s Flo-Coat galvanized steel tubing.

Salt Spray Tests

G-90 100%
White Rust
10% Red Rust

405 Hours

Flo-Coat Galvanized Steel
20% White Rust
1st Sign of Red Rust

840 Hours

Benefits of Using Allied Tube’s Construction Material:

  • Superior corrosion protection
  • Controlled zinc weight
  • Greater yield and tensile strengths
  • Controlled steel properties
  • Tube certifications available
  • Nationwide distribution capabilities

Fabrication Options:

  • Swaging
    Rounds or rectangles swaged to fit square openings
  • Stenciling
    Standard industry or custom stenciling
  • Cutting
    Secondary saw cutting to meet precise length tolerance
  • Punching
    Standard and custom hole configurations

Roll Formed Products

Some typical roll-forming products include:

  • C Purlin
  • Z Purlin
  • Hat Channel

Engineered Products

From simple to complex, Allied can provide custom roll forming to your exact specifications. Don’t have specs? We can help – by taking your idea from a concept to an engineered part.

Superior Quality

Allied’s new roll-former provides a smooth, attractive surface finish, and can hold exceptionally tight tolerances and sharp contours. You have a choice of materials such as aluminum, steel, galvanized steel, or stainless steel and we can also offer in-line powder coating – clear or colors. Our state-ofthe-art equipment allows us to pass our low costs on to you.


Wall Thickness:

Strip Width:

Material Strength:



Up to 0.156”

Up to 18”

Up to 80 ksi tensile

20     16

2″    3.5″

Review Sonco’s bundle quantity charts based on steel tubing size and shape.

SHAPES *Square tubing is available as round-to-square, weld-in-corner, or both.


Shaped Tubing Gauge Nom. Dec. 20 .035 19 .042 18 .049 17 .058 16 .065 15 .072 14 .083 13 .095 12 .109 11 .120 10 .134
Outside Diameter 0.750 SQ
0.875 SQ
1.000 SQ
1.250 SQ
1.500 SQ
1.750 SQ
2.000 SQ
2.250 SQ
2.500 SQ
3.000 SQ
4.000 SQ
0.750 x 1.500 RCT
1.000 x 1.750 RCT
1.000 x 2.000 RCT
1.500 x 2.000 RCT
1.500 x 2.500 RCT
1.500 x 3.000 RCT
1.500 x 3.500 RCT
2.000 x 3.000 RCT
2.000 x 4.000 RCT

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