A513 Cold Roll Carbon Steel Round Tubing 2-1/2 in OD 36 in Length

Our review of the A513 Cold Roll Carbon Steel Round Tubing finds it best suited for fabricators, HVAC technicians, and automotive DIYers who need a sturdy, precise section of welded tubing. The single biggest reason to buy this tubing is its combination of cold rolled strength and a drawn-over-mandrel bore that delivers a smoother inner surface and consistent wall thickness, making it reliable for fluid lines, shafts, and structural uses where rigidity and predictable dimensions matter.

Key Features

• A513 grade steel: Provides high strength and rigidity appropriate for mechanical and structural projects where durability matters.
• Drawn over mandrel: Delivers a smoother bore than standard welded tubing, reducing turbulence and easing fit for inserts or seals.
• Cold rolled finish: Increases yield strength and hardness over hot rolled alternatives, so the tubing holds shape under load.
• Precise dimensions: With a 2-1/2 in outside diameter, 2.125 in inside diameter and 0.1875 in wall, the tube works well where predictable clearance and wall retention are required.
• ASTM A513 compliance: Meets a recognized quality standard which helps when specifying material for HVAC or automotive air conditioning lines.
• 36 in length: A convenient one-piece length for many repairs and fabrication tasks without immediate need to join sections.

Who It's For

This tubing is aimed at professionals and experienced hobbyists who need a solid, drawn welded tube for applications like automotive air conditioning lines, fuel tank fittings, shafts, or small structural members. The combination of 1018-style carbon steel characteristics and the D.O.M. process makes it a good fit where strength and a smoother bore are required.

Those who should look elsewhere include projects requiring superior weldability or extensive machining ease, and applications that must use stainless or nonferrous alloys for corrosion resistance or food-grade service. Also consider seamless tubing if absolute uniformity without a weld is critical.

Pros & Cons

Pros

• Strong, rigid material that performs well under mechanical load and in structural uses.
• Smoother bore from the drawn-over-mandrel process improves flow and fit for inserts or seals.
• Cold rolling increases hardness and yield strength compared with hot rolled tubing.
• Good value for common industrial and automotive applications.

Cons

• Carbon A513 steel has slightly lower machinability and weldability than some low-carbon alternatives, which can slow fabrication in some shops.
• Some users report the inner diameter can be slightly smaller than expected, so measure before final assembly.

Specifications

Our Verdict

The A513 Cold Roll Carbon Steel Round Tubing is recommended for technicians and fabricators who need a durable, consistent tubular section for HVAC, automotive, or general mechanical work. Its cold rolled strength, D.O.M. bore, and ASTM A513 compliance make it a practical, cost-effective choice for repairs and small builds where corrosion resistance is not the primary concern.

Frequently Asked Questions

Is this tubing suitable for automotive fuel or AC lines?
Yes, customers report successful use in fuel tank and automotive AC applications, though check fittings and seals for compatibility.

Can this tubing be welded and machined easily?
It can be welded and machined, but A513 carbon steel has slightly lower machinability and weldability than some low-carbon grades, so adjustments may be needed.

Does the internal diameter match nominal dimensions exactly?
Most buyers find dimensions accurate, but some note the inner diameter can be slightly smaller than expected, so verify before final assembly.