OnlineMetals A500/A513 Carbon Steel Rectangular Tubing - Solid

In this review the OnlineMetals A500/A513 carbon steel rectangular tubing is examined for fabricators, hobbyists, and builders who need a reliable structural section. The bottom line: this 2 in x 4 in, 0.1875 in wall, 36 in length tube delivers the kind of strength and weldability expected from A500/A513 steel at a low cost, making it an excellent pick when straight, unpolished hot rolled sections are required. For anyone building frames, supports, or fittings where predictable performance and size matter, this tubing is a practical, value-oriented option.

Key Features

• A500/A513 steel: Provides good strength and predictable mechanical performance for structural and fabrication tasks.
• 2 in x 4 in profile: Offers a rectangular footprint that works well for frames, rails, and supports where one direction needs greater load capacity.
• 0.1875 in wall thickness: Balances weight and rigidity for many light to medium structural uses without excessive material cost.
• 36 in length: Ships as a manageable one-piece section that fits into workshop layouts and reduces on-site splicing.
• Hot rolled, mill finish: Arrives with a work-ready surface that welds and paints well, keeping prep time to a minimum for many projects.
• Meets ASTM A513: Ensures industry-standard dimensions and material behavior for consistent results in assemblies.

Who It's For

The tubing is aimed at steel fabricators, contractors, and DIY metalworkers who need an economical structural tube that is easy to weld and integrate into frameworks, railings, or trailer components. Its size and wall thickness suit furniture frames, small structural supports, and automotive or appliance repair where rectangular sections are preferred.

Those seeking a finished appearance right out of the box or precision cold-drawn surface finishes should look elsewhere, since this is hot rolled with a mill finish intended for functionality rather than decorative use.

Pros & Cons

Pros

• Good combination of strength and weldability for structural and fabrication work.
• Well sized at 2 in x 4 in with 0.1875 in wall for versatile light-to-medium duty applications.
• Customers report clean, rust-free arrival and solid welded quality, offering dependable value for money.

Cons

• Mill finish and hot rolled surface are not polished or decorative, which may require additional finishing for visible projects.

Specifications

Material Standard	A500/A513 (meets ASTM A513)
Finish	Unpolished (mill) finish, hot rolled
Height	2 in
Width	4 in
Wall Thickness	0.1875 in
Length	36 in

Our Verdict

The OnlineMetals A500/A513 rectangular tubing is a solid, cost-effective choice for anyone who needs structurally capable steel that welds and machines predictably. It is especially good value for fabricators and hobbyists who prioritize strength and fit over surface finish, and it delivers reliable performance for frames, supports, and repair work without unnecessary expense.

Frequently Asked Questions

Is this tubing ready to weld?
Yes, the hot rolled mill finish arrives ready for welding and general fabrication; light cleaning may be desired depending on shop practices.

Is the size exact for shop cutting and fit-up?
The product meets A500/A513 dimensional expectations for consistent fit-up, making it suitable for straightforward cutting and assembly.

Will it resist rust in outdoor use?
As hot rolled carbon steel it is not stainless; it will need paint or coating for long-term outdoor corrosion protection.