Traditional hydraulic lines use a single flared end and are usually manufactured to SAE-J525 or ASTM-A513-T5, materials that are difficult to source domestically.OEMs seeking domestic suppliers can substitute tubing manufactured to SAE-J356A specifications and sealed with O-ring face seals, as shown.Made by Tru-Line.
Editor’s Note: This article is the first in a two-part series on the market and production of fluid transfer lines for high pressure applications.The first part discusses the situation of domestic and foreign conventional product supply bases.The second part discusses the details of less conventional products targeting this market.
The COVID-19 pandemic has caused unexpected shifts in many industries, including the steel pipe supply chain and pipe manufacturing process.From the end of 2019 to the present, the tubing market has experienced disruptive changes to both factory and logistics operations.A long-simmering issue has come into the limelight.
The workforce is now more important than ever.The pandemic is a human crisis, and the importance of health has changed the work-life-play balance for most, if not all.The number of skilled workers has decreased due to retirement, some workers unable to return to old jobs or find new jobs in the same industry and many other factors.In the early days of the epidemic, the shortage of workers was mainly concentrated in industries that rely on front-line work, such as medical care and retail, while manufacturing workers were on furlough or significantly reduced working hours.Manufacturers are now having trouble recruiting and retaining staff, including experienced pipe mill operators.Tube manufacturing is largely a hands-on, blue-collar job that requires painstaking effort in an unclimate-controlled environment.Wear extra personal protective equipment (i.e. masks) to mitigate infection and follow extra rules, such as staying 6 feet long.Linear distance from others can add stress to a job that already has many stress lifters.
Steel supply and raw steel costs have also changed during the pandemic.For most tubing, steel is the largest component cost.As a rule of thumb, steel accounts for 50% of the cost per foot of pipe.Until the fourth quarter of 2020, US domestic cold rolled steel prices averaged around $800/t for three years.By the end of 2021, prices fell to $2,200 per ton.
Given how these two factors have changed during the pandemic, how are companies in the tubing market responding?What impact are these changes having on the tubing supply chain, and what useful guidance is there for the industry to emerge from this crisis?
Many years ago, a senior pipe factory executive summed up his company’s role in the industry: “We only do two things here – we make pipes, and we sell them.” , too many distractions, too many factors that weaken the company’s core values, or the current crisis (or all of these factors, which is often the case) is of value to managing executives who are overwhelmed.
It’s important to achieve and maintain control by focusing on what’s important: the factors that affect manufacturing and selling quality tubes.If a company’s efforts aren’t focused on these two activities, it’s time to go back to basics.
As the pandemic spreads, pipe demand in some industries has dropped to almost zero.Auto factories and companies in other industries deemed insignificant are sitting idle.There was a time when many in the industry neither made tubing nor sold it.The pipe market continues to exist for only a few essential businesses.
Fortunately, people are doing their thing.Some people purchase additional freezers to store food.The housing market takes off later and people tend to buy some or many new appliances when they buy a home, so both trends support the demand for smaller diameter tubing.The agricultural equipment industry is starting to recover, with more and more owners wanting small tractors or zero-turn lawn mowers.The auto market then restarted, albeit at a slower pace due to factors such as chip shortages.
Figure 1. SAE-J525 and ASTM-A519 are established as general replacements for SAE-J524 and ASTM-A513T5.The main difference is that SAE-J525 and ASTM-A513T5 are welded, not seamless.Sourcing difficulties such as six-month lead times have created opportunities for two other tube products, SAE-J356 (delivered in straight tube) and SAE-J356A (delivered in coil), which meet many of the same Require.
The market has changed, but the guidelines are the same.Nothing is more important than focusing on making and selling pipes according to market demands.
The “make or buy” question arises when manufacturing operations face higher labor costs and fixed or declining internal resources.
Manufacturing post-welded tubular products requires significant resources.Depending on the output and production of the plant, it is sometimes an economical advantage to cut wide strips in-house.However, internal slicing can be a burden, given labor requirements, tool capital requirements and broadband inventory costs.
On the one hand, cutting 2,000 tons a month results in 5,000 tons of steel in stock, occupying a lot of cash.On the other hand, very little cash is required to purchase wide cut steel in an instant arrangement.In fact, given that the tube producer can negotiate credit terms with the slitter, it can actually delay the cash outlay.Every tube mill is unique in this regard, but it’s safe to say that nearly every tube producer has been impacted by the COVID-19 pandemic relative to skilled labor availability, steel costs, and cash flow.
The same goes for tube production itself, depending on the situation.Companies with extensive value-added chains may opt out of the pipe manufacturing business.Instead of making pipe and then bending it, coating it and making sub-assemblies and assemblies, buy the pipe and focus on other activities.
Many companies producing hydraulic components or automotive fluid handling tube bundles have their own tube mills.Some of these factories are now liabilities rather than assets.Consumers in the pandemic era tend to drive less, and auto sales forecasts are a far cry from pre-pandemic levels.The auto market is associated with negative terms like shutdowns, severe declines and shortages.There is nothing to suggest that the supply situation of automotive OEMs and their suppliers will change significantly in the near future.Notably, more and more EVs in this market have fewer steel tube powertrain components.
Captive tube mills are usually built from custom designs.This is an advantage for its intended use – making pipes for a specific application – but a disadvantage in terms of economies of scale.For example, consider a tube mill designed to make 10mm OD products for a known automotive project.The program guarantees quantity-based settings.Later, a much smaller procedure was added for another tube with the same outer diameter.Time passed, the initial plan expired, and the company didn’t have enough volume to justify the second plan.Setup and other costs are too high to justify it.In this case, if the company can find a capable supplier, it should try to outsource the project.
Of course, the computation doesn’t stop at the cutoff.Finishing steps such as coating, cutting to length and packaging add considerable cost.As the saying goes, the biggest hidden cost of pipe manufacturing is handling.The tube is moved from the mill to the warehouse, where it is removed and loaded onto a workbench for final length cutting, then the tubes are layered to ensure that the tubes are fed into the cutting machine one by one – all of this The steps all require labor. This labor cost may go unnoticed by an accountant, but it comes in the form of an extra forklift operator or an extra person in the transportation department.
Figure 2. The chemical compositions of SAE-J525 and SAE-J356A are nearly identical, helping the latter to replace the former.
Hydraulic tubing has been around for thousands of years.The Egyptians hammered out copper wire more than 4,000 years ago.Bamboo thread was used in China during the Xia Dynasty, around 2000 BC, and later Roman plumbing systems were built with lead conduits, a by-product of the silver smelting process.
seamless.Modern seamless steel pipes made their North American debut in 1890.From 1890 to today, the raw material for this process is a solid round billet.Innovations in continuous casting in the 1950s led to the transformation of seamless tubes from ingots to what was then a low-cost steel raw material, billets.In the past and present, hydraulic tubing is made by cold drawing the seamless hollows produced by this process.In the North American market, it is classified as SAE-J524 by the Society of Automotive Engineers and ASTM-A519 by the American Society for Testing and Materials.
Producing seamless hydraulic tubing tends to be a labor-intensive process, especially for small diameters.It requires a lot of energy and requires a lot of space.
welding.In the 1970s, the market changed.After dominating the steel pipe market for nearly 100 years, seamless slippage.It was knocked out by welded pipe, which was found to be suitable for many mechanical applications in the construction and automotive markets.It even took some territory in what was formerly holy land – the oil and gas pipeline sector.
Two innovations contributed to this change in the market.One of them involves continuous slab casting, which enables steel mills to efficiently mass-produce high-quality flat strip.Another process that makes high frequency resistance welding a viable process for the pipe industry.The result is a new product: performance as good as seamless steel pipe compared to comparable seamless products, and at a lower cost.This tube is still manufactured today and is classified as SAE-J525 or ASTM-A513-T5 in the North American market.Because the tube is drawn and annealed, it is a resource-intensive product.These processes are not as labor- and capital-intensive as seamless processes, but the costs associated with them are still high.
From the 1990s to the present, most of the hydraulic line pipes consumed in the domestic market, whether seamless drawn (SAE-J524) or welded drawn (SAE-J525), are imported.This may be the result of the huge difference in labor and steel raw material costs between the U.S. and exporting countries.For the past 30 to 40 years, these products have been available from domestic producers, but they have never been able to establish themselves as dominant in this market.The favorable cost of imported products is a formidable hurdle.
current market.Consumption of seamless, drawn and annealed product J524 has been decreasing over the years.It is still available and has a place in the hydraulic line market, but OEMs usually choose J525 if the welded, drawn and annealed product J525 is readily available.
The pandemic hits and the market changes again.The global supply of labor, steel and logistics is declining at about the same pace as the aforementioned decline in demand for automobiles.The same is true for the supply of imported J525 hydraulic tubing.Given these events, the domestic market appears to be primed for another market shift.Ready to produce another product, one that is less labor intensive than welding, drawing and annealing tube?One exists, although it is not commonly used.It is SAE-J356A, which meets the requirements of many hydraulic applications (see Figure 1).
Specifications published by the SAE tend to be short and simple, as each specification defines only one process for making pipe.The downside is that J525 and J356A have considerable overlap in dimensions, mechanical properties, etc., so specifications tend to sow the seeds of confusion.In addition, J356A is a coiled product for small diameter hydraulic lines and is a variant of J356, which is a straight pipe product mainly used in the manufacture of large diameter hydraulic lines.
Figure 3. Although welded and cold drawn tubes are considered by many to be superior to welded and cold set tubes, the mechanical properties of the two tube products are comparable.Note: The imperial value in PSI is a soft conversion of the specification, it is a metric value in MPa.
Some engineers believe the J525 excels in high pressure hydraulic applications, such as those used in heavy equipment.J356A is lesser known, but it is also a high pressure fluid carrying specification.Sometimes final forming requirements are different: J525 has no ID bead, while J356A is flash controlled and has a smaller ID bead.
The raw materials have similar properties (see Figure 2).Small differences in chemical composition are related to the desired mechanical properties.In order to achieve certain mechanical properties, such as breaking strength in tension or ultimate tensile strength (UTS), the chemical composition or heat treatment of the steel is limited to produce certain results.
Tubing types share a common set of similar mechanical performance parameters, making them interchangeable in many applications (see Figure 3).In other words, if one is unavailable, the other is likely to meet the requirements.No one needs to reinvent the wheel; the industry already has a set of strong, balanced wheels at its disposal.
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