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Understanding Tube and Pipe Manufacturing Process

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Understanding Tube and Pipe Manufacturing Process

There’s probably nothing more critical to the success of modern infrastructure than simple steel pipes. Steel pipes are used widely in applications from underground water and power lines to sewers and drains. There are over 2.5 million miles of pipe in the oil and natural gas industry alone, not counting millions of miles more in water systems and other infrastructure networks.

But how are those pipes manufactured? How did the industry grow to be able to provide almost countless miles of pipes and tubes? The process of manufacturing stainless steel tubes and pipes has evolved along with advancements in industrial technology. In this article, we’ll outline some of that process.

Which Raw Materials Are Used?

The basic raw material used in the production of tubes and pipes is steel. Steel is an alloy composed of aluminum, titanium, manganese, zirconium, vanadium, and tungsten. Finished pipes frequently have an outer coating as well. This coating can be an advanced carbon coating to increase the durability of the pipe, or something as simple as a coat of paint.

The Tube and Pipe Manufacturing Processes

Steel pipes can be produced by a number of different methods. Here are some of the most common and efficient pipe manufacturing processes.

Mannesmann Plug Mill Manufacturing Process

This method was founded by Mannesmann, a German engineer. It starts with a cylindrical steel billet, which is pierced and fed between two rollers. At the same time, a cone-shaped mandrel is inserted into the billet. After being pierced, the billet undergoes another rolling stage in which it is elongated. A third rolling process in a plug mill completes the initial stage of the pipe manufacture. It finishes with heat treatment and undergoes a cooling, slicing, and straightening process.

Mandrel Mill Process

Like the Mannesmann process, mandrel mill pipe manufacturing begins with a hot steel billet. After heating, the billet is pierced and fed into a mandrel mill through multiple pairs of rollers. Afterward, the pipe is heat-treated and stretched, before being cooled, cut, and straightened. Unlike the Mannesmann milling process, in most cases, the desired diameter is achieved in a single attempt.

Extrusion Process

Extrusion pipe manufacturing uses hydraulic power to push a mandrel through a heated billet. By doing this within a large die, excess material is trapped between the mandrel and the walls of the die, extending and hollowing-out the billet and producing a pipe.

Forged Seamless Pipe Manufacturing Process

A heated billet is used in the process. The hot billet is placed in the forging die, which has a slightly larger diameter than the finished pipe. A hydraulic building hammer with matching interior diameter helps to create a cylindrical forged pipe. The pipe is then machined to arrive at the final dimensions. The process is efficient in the production of seamless pipes with large diameters.

Welded Pipe Manufacturing Process

Unlike some of the other processes mentioned, welded pipes are made using metal plates or coils, rather than billets. The coil or plate is rolled into a circular section. After rolling the circular section from the plate, the plate is welded. Advantages of this method include a less complicated manufacturing process and easily available material. The pipes can be produced in large sizes without any restrictions. Pipes that are welded with filler materials can be used in the manufacturing of long radius elbows and bends.

These are some of the methods that are currently used to produce large-diameter industrial metal pipes and tubing. These processes are constantly evolving, and new methods – such as 3D printing – show promise.


Bailey Hudson is a freelance industrial writer who focuses on quality industrial equipment and modern manufacturing. Bailey is currently writing for SummitMT.

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8 Strategies to Navigate Trade and Tariff Volatility

A steady drumbeat of tariffs, changing trade policy and an overall environment of uncertainty are leading many manufacturers to take a “wait and see” approach to investment and expansion. Companies are reassessing spending plans, finding it challenging to adjust how they do business on the fly in response to unsettled trade policies.

Manufacturers have seen the effects in the cost of raw materials, which has led customers with long-term pricing agreements to push back. Some are finding they need to negotiate changes to contract terms, while others are faced with locating new supply sources. However, these are difficult changes to make, and companies are unsure whether to push forward as uncertainty over tariff amounts, origin, timing and related retaliation persists.

As a result, manufacturers are hesitant to commit to large investments or expansion plans unless they can be certain they’ll see a long-term payoff. Whether manufacturers need to change their supply chain strategy, find alternative sourcing or re-source materials, they don’t feel confident implementing these initiatives without more evidence of stability in trade policy.

While the next round of tariffs may be out of manufacturers’ control, they can be proactive in preparing for changing trade policies by considering these steps to weather the storm:

Renegotiate rates with suppliers
Even if a manufacturer’s products aren’t direct tariff targets, they may include affected materials like steel and aluminum, resulting in higher cost of goods and materials. Now is the time to renegotiate terms with suppliers and try to lock them into long-term deals with favorable pricing. It may be easier said than done in many cases, particularly in cases where suppliers are using the assessment of new tariffs as an opportunity to raise prices. It’s critical manufacturers incorporate key protection clauses to avoid major price spikes that would be damaging to their business model when entering into an amended, extended or new supply contract.

Evaluate profit margins
With tariffs increasing the costs of goods and materials, it’s imperative for manufacturers to examine which costs they can absorb and which they’ll need to pass on to customers. This process involves understanding where a manufacturer might offset material cost increases with other efficiencies or cost rationalization, and the level of cost increase customers will tolerate. In customer contracts that have price escalation clauses or limitations, manufacturers may need to attempt to renegotiate clauses that prevent recovery of tariffs paid.

Consider free-trade zone opportunities
Too often, manufacturers overlook available opportunities provided by free-trade zones. The free-trade zone option allows companies to develop a product, then export it to a U.S. customs territory or foreign destination, potentially bypassing any tariffs on the product if it has been transformed.

Establish a dedicated trade and customs compliance group
Consider forming a trade compliance group with clear governance. Charge this group with developing strong “what-if” capabilities to understand the impact of various tariff and trade scenarios, including inventory and supply chain strategies, sourcing alternatives and modeling multiple data sources.

Take advantage of exclusion processes
When granted, exclusions apply retroactively to the date a tariff became effective. The Commerce Department reviews exclusion requests for Section 232 Steel and Aluminum tariffs, while the United States Trade Representative (USTR) provides a mechanism to request exclusions for Section 301 (China) tariffs. The Commerce Department has shown a willingness to provide exemptions in certain cases, particularly since March when the tariffs of 25 percent on steel and 10 percent on aluminum went into effect, making it all the more important for manufacturers to evaluate opportunities for exclusions.

Assess imported product classifications
Each product’s classification dictates whether or not it is included in the tariff order. Whether there is an accidental misclassification, an intentional misclassification by the overseas seller or a product that falls within a gray area, an audit of the classifications of imported goods will help manufacturers elude surprises and potential liabilities – and could even result in the avoidance of higher tariffs.

Import sooner versus later
Manufacturers with source material subject to the 10 percent tariff may want to procure more before the tariff leaps to 25 percent.

Seek out alternative sources of supply
Manufacturers should explore alternate supply sources to shield their business from the disruption caused by tariffs. They should be prepared to onboard new supply partners quickly – a process that might include partner profiles, legacy systems, custom coding and new systems to securely exchange order, invoicing, shipping and payment data.

Time will tell the extent to which new tariffs and trade policy will impact the manufacturing industry. Regardless of today’s uncertainty, manufacturers should take steps now to prepare and protect their business interests amid the shifting trade environment.