The outside diameter of the ASTM A513 tube is 21.3mm-406.4mm, and wall thickness schedules are SCH10 to SCHXXS. Made from carbon steel grades 1010, 1015 and 1020, this electric-resistance-welded mechanical tubing provides tight dimensional tolerances for easy precision machining, bending and forming. So whether you’re sourcing automotive bushings, structural brackets or fitness equipment frames, knowing the full size range lets you match the right tube spec to your production requirements from day one.
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ASTM A513 Tube Dimensions
The first step to a sound procurement decision is to know the dimensional framework of A513 mechanical tubing. This standard applies to electric-resistance-welded carbon steel tubing made primarily for mechanical applications where dimensional uniformity is more important than pressure ratings.
Outside Diameter Range
Longma Group offers ASTM A513 tube with outer diameters from 21.3 mm to 406.4 mm. This range extends from small-bore shaft sleeves to large-diameter structural parts for agricultural machinery and automotive subframes. OD tolerances are held to very tight limits, usually ±0.5% or better depending on the type of production.
Wall Thickness Schedules
Wall thickness is indicated by schedule designations from SCH10 to SCHXXS. SCH10 is intended for light duty forming and ornamental applications, while SCHXXS offers a maximum wall thickness for heavy load-bearing or high-pressure machining environments. The material weight, machinability and finished part strength are all directly impacted by the choice of schedule.
Type Classification and Dimensional Impact
The ASTM A513 specification covers Type 1 (Hot Rolled, ERW), Type 2 (Cold Rolled, ERW) and Type 5 (Drawn Over Mandrel, DOM). Type 5 DOM tubing has the tightest OD and ID tolerances, frequently in the ±0.003-inch range, and is the preferred option for automated CNC machining operations where concentricity is a critical factor.
Key Mechanical and Chemical Properties Related to Tube Size Selection
If you do not choose an ASTM A513 tube dimension that considers the properties of the underlying material, the component may fail prematurely. At the design-to-procurement stage, the relationship between tube geometry and material behavior should be carefully examined.
Yield and Tensile Strength by Wall Thickness
Heavier wall schedules have more load capacity. Yield strengths for grade 1020 are typically in the 50,000-65,000 psi range depending on the method of production and heat treatment. 1020 has higher yield but lower cold-forming ductility than 1010 due to higher carbon content. The engineer should specify wall thickness according to actual service load rather than specify the heaviest schedule available.
Chemical Composition and Dimensional Stability
The basic differences between 1010, 1015, and 1020 are the carbon content, which varies from about 0.08 to 0.23 percent and controlled amounts of manganese, phosphorus and sulfur. The higher carbon content (1020) results in higher surface hardness after cold working, and the lower carbon grades (1010) limit the potential for weld zone cracking in fabrication. Consistent chemistry from batch to batch is critical to provide predictable machining behavior from production run to production run.
Work Hardening and Surface Quality
Cold rolling in Type 2 and DOM Type 5 production creates work hardening that increases surface hardness without heat treatment. This means better wear resistance on the bearing surfaces of tube inner diameters. Surface finish on DOM tubing is usually Ra 1.6 µm or better, eliminating secondary grinding operations on precision components.
Comparing A513 Tube Sizes with Alternative Tubing Standards
Before finalizing a material specification, purchasing managers often look at A513 along with other standards that are close by. Each standard is in a different place when it comes to the accuracy of measurements and the purpose for which it was made.
- ASTM A500 (Cold-Formed Structural Tubing): Primarily rectangular and square sections for structural frameworks. Wall thickness tolerance allows up to 10% variation under nominal, which is less suitable for close-tolerance machining. Grade B minimum yield is 46,000 psi for round tube.
- DOM / Cold-Drawn Seamless (CDS): Tightest tolerances of all categories but significantly higher cost. DOM is technically produced under the A513 specification as Type 5, bridging precision and cost. CDS is reserved for the most demanding applications where weld seam presence is unacceptable.
Because of these differences, A513 is the best choice for corporate buyers who need to balance the accuracy of the dimensions with the cost of buying in bulk. You would have to pay extra for features you don't need if you chose ASTM A500 for a machined bushing or CDS for a furniture rail.
Factors Influencing Procurement Decisions: Size, Thickness, and Customization
Getting the right tube on time and in the right size is just as important as following the specs. When you place an order for ASTM A513 tube, a number of purchasing factors come together.
Application-Driven Size Selection
For automotive bushings, OD tolerances must be within 0.1mm and the ID finish must be consistent. For structural brackets, the tolerances are a little wider. When it comes to welding quality, fitness equipment frames put an emphasis on smooth surfaces and consistent wall thickness. When the type of tube and plan are matched to the real production process, there is no need for expensive rework.
Minimum Order Quantities and Lead Time
One of the main things that mid-sized producers worry about is whether or not a source will take small test orders. Longma Group keeps 100–200 tons of stock in common sizes and grades 1010, 1015, and 1020. This lets us fulfilll small orders without making big commitments. Our fastest delivery time is seven days for sizes that are in stock.
Custom Length and Surface Treatment Options
Standard mill lengths are 6 meters, but you can get lengths that are cut just for you to cut down on waste. Options for treating the surface, such as hot-dip galvanizing, make it more resistant to rust for use outside. These options can be used without placing full-container orders, which allows manufacturers with different production schedules to really benefit from flexible procurement.
Ensuring Quality and Compliance of A513 Tubes in Specified Sizes
Quality documentation and dimensional traceability are non-negotiable in B2B steel procurement, especially for buyers managing multi-tier supply chains.
Dimensional Inspection Methods
Each production batch undergoes dimensional checks using calibrated measuring instruments for OD, ID, wall thickness, and straightness. Ultrasonic testing verifies wall uniformity and detects internal discontinuities before shipment. These steps confirm that the tube you receive matches the certificate values.
Certifications and Traceability
Longma Group holds ISO 9001 Quality Management System certification and API 5L certification, with full material test certificates (MTC) provided for every order. Heat numbers are traceable from raw material sourcing—drawing from mills including Baosteel, HBIS, and Shagang—through to the finished tube, giving quality managers a complete audit trail.
Supplier Evaluation Criteria
Beyond price, buyers should assess whether a supplier provides manufacturing procedure specifications (MPS), inspection and test plans (ITP), and after-shipment support. Longma Group provides all three as standard documentation, reducing the administrative burden on procurement teams handling international transactions.
Conclusion
There are three main things you need to consider when choosing the right ASTM A513 tube: the range of sizes that work for your machining process, the wall schedule that meets your load needs, and a provider that has the stock depth and documentation standards to support your production plan. It comes in stock in grades 1010 through 1020 and ODs ranging from 21.3mm to 406.4mm. This means that it can be used in most industrial production situations. Longma Group combines checked material sourcing, quality systems that are certified, and flexible order fulfillment to meet the real needs of purchasing managers who can't have surprises about sizes on the shop floor.
FAQ
What outside diameter range is available for ASTM A513 tube?
Outside sizes of ASTM A513 mechanical tubing range from 21.3 mm to 406.4 mm. This range includes most industrial uses, from small precision parts to bigger structural and farm equipment parts.
How does wall thickness affect the strength of A513 tubing?
It is better for rigidity and yield strength to have thicker wall schedules. When cold-worked, grade 1020 can have a yield strength of more than 65,000 psi. Thinner plans are easier to shape and lighter, so they can be used for twisting and making decorations.
Can I order custom lengths for A513 mechanical tubing?
Yes. Standard mill lengths are usually 6 meters, but some providers, like Longma Group, offer custom cut-to-length services that can help you meet your production needs without having to place big minimum orders.
What is the difference between Type 1 and Type 5 A513 tubing?
Type 1 is ERW tubing that has been hot-rolled and has standard tolerances. After welding, Type 5 (DOM) is drawn over a mandrel to get tighter OD and ID tolerances—often within ±0.003 inches—and a cleaner internal surface. This makes it the best choice for precision machining.
What grades of carbon steel are available under ASTM A513?
The 1010, 1015, and 1020 marks are the most popular ones. The grade you choose will depend on the balance of ductility, machinability, and surface hardness that you need for your part design.
Request Your A513 Tube Quote from Longma Group
From 2003 to now, Longma Group has sold A513 mechanical tubing to companies in more than 90 countries. We have 100–200 tons in stock, in grades 1010, 1015, and 1020, with ODs ranging from 21.3mm to 406.4mm and delivery times starting at 7 days. This means we can meet your exact needs and meet your deadline without any problems. As an ISO 9001- and MTC-certified ASTM A513 tube supplier you can trust, we are ready to help you with your next order. To get a price right away, email your question to info@longma-group.com or go to longma-group.com.
