A513 Cold Roll Carbon Steel Round Tubing 1.375in OD - Durable Build

Our review of the A513 cold roll carbon steel round tubing finds it best suited for builders, fabricators, and HVAC technicians who need a stiff, consistent tube for mechanical and fluid applications. The single biggest reason to buy is its combination of cold rolled strength and a drawn-over-mandrel weld that produces a smoother bore and more consistent wall than ordinary welded tubing, making it a reliable choice where rigidity and predictable dimensions matter.

Key Features

• Material and strength: Cold rolled A513 carbon steel offers higher yield strength and hardness than hot rolled alternatives, which helps parts resist bending under load.
• Drawn over mandrel weld: The drawn-over-mandrel process yields a smoother internal bore and a more consistent wall thickness than typical welded tubing, improving flow and fit for inserts.
• Dimensional consistency: With a 1.375in outside diameter and 0.065in wall, the tube delivers predictable sizing for machining, press fits, and assembly operations.
• Application-ready length: The 48in length is practical for cutting multiple parts, mockups, or direct installation in HVAC and automotive runs without excessive waste.
• ASTM A513 compliance: Meeting ASTM-A513 gives confidence in material and manufacturing quality for many industrial uses.

Who It's For

This tubing is aimed at professionals and hobbyists who need a robust, machinable carbon steel tube for shafts, pins, small structural elements, or fluid lines in automotive and HVAC projects. Its strength and smooth bore make it particularly useful for fuel tank fittings, air conditioning lines, and any application requiring consistent wall thickness.

Those who should look elsewhere include projects requiring high weldability or ease of machining as primary concerns, or applications that demand stainless steel corrosion resistance; A513 is a higher carbon steel with slightly reduced weldability and machinability compared with some low-carbon grades and stainless alloys.

Pros & Cons

Pros

• High strength and rigidity from cold rolling make it durable for structural and rotating parts.
• Smoother bore and consistent wall thickness thanks to the drawn-over-mandrel weld process.
• Good value for money with quality steel suitable for automotive HVAC and fluid transfer uses.

Cons

• Higher carbon content reduces weldability and can make machining slightly more difficult than lower-carbon alternatives.
• Some users report the inner diameter can be marginally smaller than expected, which may affect tight-fit inserts.

Specifications

Our Verdict

The A513 cold roll carbon steel round tubing is a solid, cost-effective choice for technicians and fabricators who need a stiff, consistent tube with a smooth bore and reliable wall thickness. Buy it when strength, dimensional predictability, and ASTM-A513 conformity matter; consider other alloys if weldability or corrosion resistance is the priority.

Frequently Asked Questions

Is this tubing suitable for automotive fuel lines?
It is commonly used in automotive applications and customers report successful use for fuel tank connections, but verify inner diameter and any fuel compatibility requirements for your specific system.

Can this be welded and machined easily?
It can be welded and machined, but expect slightly reduced weldability and machinability compared with lower-carbon steels; plan for appropriate welding procedure and tooling.

Does the inner diameter vary from nominal?
Most users find dimensions accurate, though some report a slightly smaller inner diameter on occasion, so measure before final assembly.