Exploring the Advantages of CDW Pipe Compared to ERW Tube

You may have wondered which type of pipe, CDW or ERW, is best suited for your project. This isn't a simple question, as we need to consider not only cost and specifications, but also tolerances, whether the welded pipe has weld defects, and whether the inner diameter is consistent.

If you're wondering, here are a few practical points you need to remember:

lIf your project is general-purpose, manufacturing-related, or involves processing, and does not require very strict inner and outer diameter tolerances, then ERW pipe is a good option.

lIf you require high precision for inner/outer diameter, concentricity, and wall thickness, CDW Pipe is your best choice.

CDW Pipe vs ERW: Key Differences

Manufacturing Process of ERW Steel Tubes and CDW Pipe

ERW Tube

In ERW steel pipe production, steel plates are formed and welded using specialized bending machines.  The ASTM A513 standard, commonly used in ERW production, specifies that ERW machine operators must classify the internal diameter burrs.

lFlash-In: inside flash may remain up to wall thickness or 3/32 in (2.4 mm) (whichever is smaller).

lFlash Controlled: can be limited to 0.010 in (0.25 mm) or 0.005 in (0.13 mm) depending on what you order.

lNo Flash: achieved by further processing such as DOM (drawn-over-mandrel).

This shows that the selection of ERW steel pipes requires high attention to detail regarding burrs.

CDW Pipe

We will use the commonly used EN 10305-2 as an example. This standard clearly states that the tubing is manufactured from electrically welded hollow blanks through a cold drawing process.Its characteristics are:

lHaving stricter size specifications.

lImprove concentricity

lA more uniform surface facilitates subsequent processing.

In the EN 10305-2 standard we cited as an example, the delivery conditions are clearly listed:

+C, +LC, +SR, +A, +N. When purchasing, you need to pay attention to whether the forming and performance conditions meet the requirements.

Mechanical Strength and Durability of CDW and ERW

Same grade, same dimensions—why did it fail sooner

This is a frequently asked question.  Generally, it's not a chemical reaction issue, but rather likely due to stress concentration, differences in shape, and surface conditions.

l We continue by looking at the EN 10305-2 standard, which explains how delivery conditions affect minimum mechanical properties.  Using E235 steel tubes as an example, this standard specifies a minimum tensile strength of 490 MPa under +C conditions and provides corresponding guidance values ​​for yield strength based on different delivery conditions.

l Under the +C condition for E355, the minimum Rm value can reach 640 MPa, but the requirements are different for the +SR/+N conditions.

From the above, it can be seen that different cold drawing processes and delivery conditions can transform the tubing from being "easily formable" to "high-strength and precise," or achieve a balance between the two, for example: stress relief + cold drawing can improve stability.

Dimensional characteristics of CDW steel pipe durability

Under normal conditions, ERW welded pipes can meet certain requirements, but premature failure of durability usually stems from the following reasons:

l ovality/out-of-round

l eccentric wall

l Some burrs have worn down the seals or caused jamming.

Cold-drawn precision tubes typically have higher concentricity and tighter tolerances, and are used in projects requiring these specifications to reduce risk.

Application Scope: CDW Pipe and ERW Steel Tubes

ERW Tube(avoid over-specifying)

If your pipe manufacturing process involves a significant amount of machining (boring, honing, turning) or is primarily used for structural or manufacturing purposes, then ERW is your best option.  Here are some common applications:

lConstruction scaffolding and supports

lNon-critical sleeves that require full machining

lMechanical components with low requirements

ERW Tube(High standards were applied in the selection process.)

When you require high precision in steel pipes (inner/outer diameter accuracy, concentricity, surface smoothness), CDW is your best choice. They are also commonly used in:

lAutomotive parts: requiring tubular parts with strict specifications and sensitivity to fatigue.

lEngineering tools: Commonly used in precision bushings, shafts, and sliding components.

lHydraulic and pneumatic systems: some pipes require hydraulic cylinders or seals.

Cost and Value Considerations

the cheapest tube becomes the most expensive part

This is a problem that frequently arises during the procurement and review process.

lHidden processing costs (additional tool wear, slower feed rates, extra deburring/cleaning)

lProduction losses (scrap, rework, production line downtime, sorting)

CDW steel pipes typically have a higher unit price because they involve additional cold working processes—but many believe that cold drawing reduces downstream machining and waste, making them worth the cost.

The correct way to compare prices is to The price of steel pipes, processing time, and scrap rate.

Choosing Between CDW Pipe and ERW

If you are wondering how to choose the right steel pipes for your project, please send your drawings (or provide outer diameter/inner diameter/quantity/material) to TORICH Group. We will be happy to assist you.We can provide you with:

lWe can confirm whether ERW pipes are suitable for your project and provide high-quality ERW pipes.

lIn which situations can using CDW pipes reduce overall costs?

lThe appropriate standards and delivery times have been confirmed, and the delivery terms have been agreed upon.

lWe provide and offer quotes for quality control solutions tailored to your risk level.

Contact us now!