OnlineMetals A500/A513 Carbon Steel Rectangular Tubing - Structural

In this review of the OnlineMetals A500/A513 carbon steel rectangular tubing, the bottom line is simple: this is a sturdy, no-frills structural tube for projects that need reliable strength and weldability without a premium finish. The reviewer finds it best suited to fabricators, metalworkers, and builders who need consistent dimensions and a hot rolled, mill finish for welding or structural use. Its biggest selling point is the familiar A500/A513 chemical and mechanical properties that make it common in North America for bridges, buildings, and appliance frames.

Key Features

• A500/A513 steel: Offers good strength and weldability, making it a practical choice for structural and fabrication work.
• Dimensions: The 2' in height by 4' in width profile with a 0.1875' in wall provides predictable load-bearing capacity for light to medium structural tasks.
• 72' in length: Long stock reduces the number of welded joints and is useful for longer runs in framing and construction.
• Hot rolled, mill finish: Arrives unpolished which is appropriate for welding, cutting, and painting rather than decorative use.
• Meets ASTM-A513: Conforms to a common industry standard, giving confidence for engineering and code-driven projects.

Who It's For

The product is aimed at contractors, metalworkers, and hobbyist fabricators who need economical, structurally rated rectangular tubing for frames, supports, and general fabrication. Its mill finish and hot rolled condition make it suited to welding and surface preparation rather than exposed architectural applications.

Those seeking a polished or decorative appearance, or specialty alloy properties (stainless or galvanized surface protection), should look elsewhere. If corrosion resistance without painting is required, galvanized or stainless tubing would be a better fit.

Pros & Cons

Pros

• Reliable structural performance thanks to the A500/A513 specification and widely understood material behavior.
• Good weldability and straightforward fabrication properties for common shop processes.
• Customers report the tubing arrives in good condition, clean and free of rust, and sized accurately for projects.

Cons

• The mill finish is unpolished and hot rolled, so it requires surface treatment or painting for corrosion protection or aesthetic use.

Specifications

Material	A500/A513 carbon steel
Finish	Unpolished (mill), hot rolled
Height	2 in
Width	4 in
Wall thickness	0.1875 in
Length	72 in
Standard	Meets ASTM-A513

Our Verdict

The OnlineMetals A500/A513 rectangular tubing is a practical, value-oriented choice for anyone who needs structurally rated steel for welding and fabrication. It delivers predictable strength and good welded quality at a low cost, though buyers should plan to finish or protect the mill surface if corrosion resistance or appearance matters. Overall, it represents solid value for builders and fabricators.

Frequently Asked Questions

Is this tubing ready to weld?
Yes. The hot rolled mill finish and A500/A513 material make it suitable for standard welding processes after normal surface cleaning.

Does it come primed or galvanized?
No. The product is unpolished mill finish and will require painting or coating for long-term corrosion protection.

Is the size accurate for structural use?
Customers report accurate dimensions and good welded quality, and the tubing meets ASTM-A513, supporting its use in structural applications.