A500/A513 Carbon Steel Square Tube 4in x 0.1875in - Structural

In this review of the A500/A513 Carbon Steel Tube-Square, the bottom line is simple: this is a sensible choice for fabricators and hobbyists who need a sturdy, economical piece of square tubing for structural work. The reviewer found the tubing's primary appeal to be its combination of good strength and weldability, which makes it useful for a range of projects from framing to appliance or automotive fixtures. For anyone seeking a no-frills, hot rolled, mill-finish steel tube in a 12in length and a 4in height, this product delivers the expected mechanical utility at a low cost.

Key Features

• Material strength: A500/A513 steel provides reliable structural strength suitable for light to moderate load-bearing fabrications.
• Weldability: The steel is easy to weld, enabling clean joints for frames, racks, and custom brackets.
• Mill finish: The unpolished, hot rolled surface reduces cost while remaining acceptable for painted or powder-coated finishes.
• Standard compliance: Meets ASTM A513 with ASTM A500 availability noted, which helps ensure consistent material properties for structural use.
• Practical dimensions: The 4in height, 0.1875in wall thickness and 12in length make it versatile for small structural assemblies and prototypes.
• Cost efficiency: As common North American steel tubing, it offers a low-cost raw material option for builders and shops.

Who It's For

The tube is well suited for metalworkers, welders, machine shops, and DIYers who need a short length of square tube for testing, bracing, or small fabrications. Its combination of strength and weldability makes it a practical pick for structural uses in buildings, bridges, or light automotive and appliance applications where exacting surface finish is not required.

Those who need stainless performance, superior corrosion resistance, or a pre-finished decorative surface should look elsewhere. Also, buyers requiring custom lengths beyond the listed 12in or highly precise cold-drawn tolerances may prefer other product families.

Pros & Cons

Pros

• Good balance of strength and weldability for structural fabrications.
• Affordable mill finish reduces overall project cost.
• Standardized to ASTM A513 with A500 availability, aiding material consistency.
• Practical 4in size and 0.1875in wall suitable for many light structural tasks.

Cons

• Mill finish can show surface oxidation; rust resistance received mixed feedback from customers.
• Only supplied as a 12in length in this listing, so not ideal if longer stock is needed.

Specifications

Material	A500/A513 carbon steel
Finish	Unpolished (mill) hot rolled
Height	4in
Wall thickness	0.1875in
Length	12in
Standards	Meets ASTM A513 (ASTM A500 call for availability)

Our Verdict

The A500/A513 Carbon Steel Square Tube is a practical, cost-effective choice for builders and fabricators who need a short run of workable square tubing. It combines useful strength and weldability with standard-compliant material properties, making it good value for structural and workshop projects that do not require advanced corrosion protection or decorative finishes.

Frequently Asked Questions

Is this tube ready to weld right away?
Yes, the hot rolled mill finish steel is weldable and commonly used for welded frames and brackets.

Will it resist rust outdoors?
The mill finish is not corrosion resistant; some customers reported rust-free pieces while others noted surface corrosion, so protective coating is recommended for outdoor use.

Are other lengths available?
This listing is for a 12in length; check availability for ASTM A500 variants or longer lengths with the supplier.