DOM Tubing Supplier | Drawn Over Mandrel Steel Tubing

DOM Tubing Supplier | Drawn Over Mandrel Steel Tubing

Solitaire Overseas is a globally trusted DOM tubing supplier with over 35 years of experience in precision mechanical tubing. We stock DOM tubing and DOM steel tubing in grades 1020 and 1026 to ASTM A513 Type 5 specifications, across a comprehensive range of DOM tubing sizes and wall thicknesses for engineering, automotive, hydraulic and structural applications. Whether you need standard stock or custom cut lengths, our team delivers with speed, consistency, competitive DOM tubing prices and full material traceability.

What Is DOM Tubing?

DOM stands for Drawn Over Mandrel. DOM tubing is a high-precision mechanical steel tube produced by cold drawing an electric resistance welded (ERW) tube through a die and over a mandrel simultaneously. The die controls the outside diameter (OD) while the mandrel controls the inside diameter (ID), producing DOM steel tubing with extremely tight dimensional tolerances, smooth inner and outer surfaces, and superior mechanical properties compared to standard ERW tubing.

DOM material is not a material grade but a manufacturing process classification. The base material is typically SAE 1020 or SAE 1026 carbon steel. The cold drawing process work-hardens the steel, increasing tensile and yield strength. It also removes the internal weld flash entirely, producing a bore so smooth it is often referred to as near seamless, although a very fine weld line does technically remain.

DOM tubing conforms to ASTM A513 Type 5, the industry standard for electric resistance welded carbon steel mechanical tubing drawn over a mandrel. European equivalents include EN 10305-2. 

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Drawn Over Mandrel Tubing Specifications

Solitaire Overseas supplies drawn over mandrel tubing to the following specifications:

DOM Material Properties

The following table summarises the typical mechanical and dimensional properties of DOM steel tubing to ASTM A513 Type 5:

DOM Tubing Sizes Available from Solitaire Overseas

We supply DOM tubing in a wide range of sizes. The table below shows representative stock dimensions. Additional sizes, heavy wall configurations, and custom cut lengths are available on request.

Note: Grade 1020 is standard for OD below 2 inches or wall thicknesses below 0.156 inches. Grade 1026 is standard for OD above 2 inches or walls heavier than 0.156 inches. Both grades are stocked. Contact us to confirm availability for your specific DOM tubing sizes.

DOM Tubing Prices

DOM tubing prices depend on several variables including outside diameter, wall thickness, grade (1020 or 1026), order quantity, and current market conditions for carbon steel strip. As a global DOM tubing supplier with direct mill relationships and large inventory holdings, Solitaire Overseas offers competitive DOM tubing prices for both small orders and bulk volume requirements.

Request a quote from Solitaire Overseas for current DOM tubing prices on your exact size, grade, and quantity. We respond to all enquiries within one business day.

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Benefits of DOM Steel Tubing

Engineers and procurement specialists specify DOM steel tubing for demanding applications because it combines dimensional precision, surface quality, and mechanical strength in a single cost-effective product. Key advantages include:

• Tight OD and ID Tolerances
  Both diameters are simultaneously controlled during cold drawing, producing concentricity and roundness that standard ERW tubing cannot achieve.
• Smooth Inner Bore
  Flash removal before drawing eliminates the raised weld seam, producing an interior surface suitable for hydraulic cylinders and bushing bores without additional honing.
• Superior Weld Strength
  The cold drawing process works the weld zone to the same density and structure as the base metal, eliminating the weld as a weak point.
• Increased Tensile Strength
  Cold working raises tensile and yield strength above the base ERW tube, enabling use in high pressure and high load applications.
• Excellent Machinability
  The dense, consistent grain structure makes DOM steel tubing highly machinable, reducing tool wear and secondary processing time.
• Near Seamless Appearance
  The weld line becomes virtually invisible after drawing, which is why DOM tubing is often specified where a seamless appearance is required.
• Cost Advantage Over CDS
  DOM tubing offers performance close to cold drawn seamless (CDS) at a lower price point, making it the preferred choice for most precision mechanical applications.
• Wide Size Range
  DOM can be produced across a very broad range of OD and wall thickness combinations, including sizes not available in seamless tubing

What Is the Drawn Over Mandrel Process?

The term drawn over mandrel describes a specific cold tube drawing technique used to manufacture DOM tubing, not a separate material grade. In this process, a pre-formed electric resistance welded tube is used as the starting material. This tube, sometimes called the mother tube or feedstock, is annealed and cleaned before drawing. One end is then pointed so that it can be gripped by the drawing mechanism.

The tube is set inside a precision carbide die that defines the outside diameter of the finished product. A carbide mandrel, sized to match the required inside diameter, is inserted into the bore. The die and mandrel work together: as the tube is pulled through, the die reduces and precisely sizes the OD while the mandrel supports the interior and controls the ID. This simultaneous inside-outside sizing is the defining feature of the drawn over mandrel process.

Multiple drawing passes may be applied depending on the amount of size reduction required, the wall thickness target, and the mechanical properties needed in the final product. Between passes, the tube may be re-annealed to restore ductility if significant reduction has been achieved.

Drawn Over Mandrel Manufacturing

• Steel Coil Slitting: Cold-rolled or hot-rolled steel coil is slit to the exact strip width required for the intended tube diameter.
• Cold Forming: The steel strip is fed through a series of contoured rolls that progressively shape it into a circular tube profile.
• ERW Welding: The strip edges are joined under high pressure using high-frequency electrical resistance welding (ERW). This creates a forged butt weld with no filler material.
• Internal Flash Removal: The internal weld flash is removed using a cutting tool, leaving a smooth bore surface ready for drawing. This step is absent in standard flash-in ERW tubing and is one of the key distinguishing features of the DOM process.
• Weld Inspection and Testing: The weld integrity is tested non-destructively before the tube proceeds to drawing.
• Annealing: The tube is passed through a controlled-atmosphere furnace, heated to the appropriate temperature, and slowly cooled. Annealing relieves residual welding stresses, homogenizes the grain structure, and restores the ductility needed for cold drawing.
• Surface Preparation: The annealed tube is cleaned, phosphate-coated, and lubricated to protect the die and mandrel surfaces during drawing.
• Cold Drawing Over Mandrel: The tube is drawn through a die and over a mandrel to produce high-precision DOM tubing with controlled OD and ID. 
• Multiple Pass Drawing (if required): For significant size reductions, the tube undergoes additional drawing passes, with intermediate annealing if required to restore workability.
• Straightening: The finished DOM tube is straightened to ASTM A513 tolerances (0.030 inch per 3-foot length for tubes up to 8-inch OD).
• Cutting and Inspection: The tube is cut to mill lengths or specified cut lengths and undergoes dimensional inspection, surface inspection, and mechanical testing.

DOM Tubing Applications

DOM tubing is used wherever precision, strength, and a clean surface finish are required. Its combination of tight tolerances, consistent DOM material properties and high machinability makes it a first-choice specification across the following industries and applications:

• Automotive and Motorsport

• Hydraulics and Fluid Power 

• Industrial Machinery and Manufacturing 

• Motorcycle and Bicycle Frames

• Aerospace and Defense (Non-Critical Structure)

• Construction and Infrastructure

DOM Tubing vs. ERW vs. Seamless: Which Should You Specify?

Selecting the correct tube type prevents over-engineering, reduces cost, and ensures the product performs in service. The comparison below covers the three most common mechanical tubing types:

Summary: For most precision mechanical, hydraulic, and automotive applications, DOM tubing offers the best balance of performance, availability of DOM tubing sizes, and cost. Specify CDS only when wall thickness requirements exceed DOM limits or when a true seamless bore is required.

Quality Standards and Certifications

All DOM steel tubing supplied by Solitaire Overseas complies with international standards and is supported with full documentation, ensuring reliability for critical applications.

Mill test certificates (MTCs) are supplied as standard with every order. Third-party inspection, additional non-destructive testing (NDT), and customer-specific documentation packages are available on request.

Why Choose Solitaire Overseas as Your DOM Tubing Supplier

We are a trusted DOM tubing supplier serving global industries since 1989. Our experience ensures accurate supply of DOM tubing, correct DOM material selection, and competitive DOM tubing prices.

• We are a trusted DOM tubing supplier serving global industries since 1989. Our experience ensures accurate supply of DOM tubing, correct DOM material selection, and competitive DOM tubing prices. 
• We hold a broad range of DOM tubing sizes in grades 1020 and 1026 for immediate dispatch, reducing lead times for your projects.
• Every lot is traceable to mill heat number with EN 10204 3.1 MTCs supplied as standard. 3.2 inspection is available on request.
• We export DOM steel tubing to customers across Asia, the Middle East, Europe, Africa, and the Americas. Our logistics team handles all documentation, packing, and shipping coordination.
• Our direct mill relationships and volume purchasing enable us to offer competitive pricing without compromising on material quality or certification.
• Our team can advise on grade selection, size availability, tolerances, and alternative specifications to help you source the right DOM material for your application.
• Cut-to-length, surface treatment, and custom packing are available to reduce your downstream processing costs.