More than 50 years of plate rolling
Aug 10, 2023
These fabrications are just some of the projects for which plate rolling is a necessary part of the overall manufacturing process. Images: Holloway Co. Inc.
The passion of the father often remains with the offspring in some way or form. Lynton Holloway, president, Holloway Co. Inc., Saginaw, Texas, literally is living that scenario today.
Lynton Holloway’s father jumped into metal fabricating because he loved making storage tanks, which led him to start his own company in 1971. Even though he had recently come from the crane rental business and would continue to dabble in that commercial activity while running his new business in its early years, Gene Holloway wanted to pursue his passion—fabricating tanks.
With experience and word-of-mouth, Holloway Co. grew. In the 1980s, the company added field erection services, allowing it to be a one-stop shop for the design, manufacturing, and erection of water storage tanks. The company also started fabricating hydropneumatic tanks (vessels designed to store water and air under pressure, which allow for the delivery of pressurized water quickly and on-demand, without the constant use of a pump) for municipalities.
By the 1990s, Holloway Co. diversified again by adding beam rolling capabilities. Adding the capability to roll structural steel for such things as roof supports for projects connected to tanks made sense for a company looking to increase its value to tank-buying customers.
In the 2000s, a large shift started to occur in terms of the future of Holloway Co. It turned out that a lot of people were interested in the company’s structural steel bending capabilities, so Holloway Co. started doing more beam fabricating for those customers. Meanwhile, the storage tank erection business had slowed to the point that the decision was made to shut down that portion of the company. Just over 20 years of plate rolling experience would need to be applied elsewhere.
Like the beam rolling business, Holloway Co. soon found that people needed plate rolling services as well. The fabricating activity that was so crucial to making Gene Holloway’s passion a reality became a key cornerstone of the company’s business today. In fact, Hunter Holloway, Lynton’s son, is now in charge of structural and plate roll sales while also acting as an estimator.
“With us doing custom plate rolling for others or for our custom tanks that we make, approximately 40% of our business is involved in plate rolling,” Lynton Holloway said. “We do keep our plate rollers busy.”
Any metal fabricator familiar with plate rolling might recognize that when it comes to plate rolling, a little patience can help turn passion into expertise.
“It’s hard to find those operators,” Holloway said. “We’ve got a few of them, but some of them hang around for a little while and decide it’s not what they want to do.”
The job is challenging. The operators are working with steel plate that doesn’t necessarily want to bend in the way that the job specifications demand.
Holloway Co. Inc., Saginaw, Texas, has been rolling plate for years. While projects have changed, the company’s quality commitment hasn’t.
Holloway said that the shop works with a lot of A516 grade 70 carbon steel plate. It’s regularly used in the fabrication of pressure vessels, particularly as it is suitable for environments where atmospheric conditions dip below ambient temperatures. The catch with the material, however, is that it has greater tensile and yield strength than grade 60 or 65 steels, making it even more challenging to form.
Additionally, Holloway Co. is an American Society of Mechanical Engineers code shop. All of the pressure vessels coming out of the shop have to be inspected before they can be shipped out. To maintain those manufacturing credentials, a shop needs to be exact in its fabricating activities.
“We have to be within so many degrees and have a percentage of roundness on those tanks,” Holloway said. “You just can’t throw it up there, and if it’s within an inch say, ‘Yeah. That will work.’”
That’s where the operator can make a difference. He won’t panic when the plate doesn’t form up exactly as the control software suggests after the initial rolls, or he can help to rework a cylinder fabrication that’s warped slightly after welding has taken place. Scrapping a large plate of a specialty alloy is not something any shop wants to do. A talented plate operator can help to avoid that.
Right now, Holloway Co. employs three full-time plate rolling machine operators. (The company has about 40 full-time employees.) They oversee four plate rolling machines.
Holloway said that the company is always looking for anyone else that might be interested in learning more about plate rolling. In fact, a couple of the operators came from welding.
A fear that the operator might not stick with plate rolling for the long term is just one of the risks of trying to groom new plate rolling talent. It’s a skill that is necessary to work with today’s challenging materials.
Luckily, plate rolling technology has evolved to help address this challenge. Holloway Co. Inc. recognized this back in the late 1990s.
In the very early days of the company’s history, Holloway Co. relied on a mechanical three-roll plate rolling machine. Let’s just say that plate bending technology has come a long way since then.
Those three-roll machines were based on an initial-pinch design, which entails introducing the plate to the rolls so that the upper roller and the roller furthest away from the material entry point grip the part, while the bottom roller nearest the material entry point performs the first prebend. But that’s not where the rolling exercise ended with the three-roll machine.
“You’d have to take out the plate, spin it around, feed it back into the machine, and prebend the other end,” Holloway recalled. Then all three rolls were used to close the cylinder.
Needless to say, that method of plate rolling, although standard for the time, was both time-consuming and awkward. Holloway said that the company was always interested in machines that would help to speed up the fabricating process and improve quality. In 1998, Holloway Co. purchased its first four-roller machine.
The four-roll machine design eliminated the need to spin the material around 180 degrees for prebending the other end. This machine allowed for a double-pinch of the material, where the upper roller and the middle-bottom roller pinched the material and locked it into place. The roller closest to the material entry point then moved to create the first prebend. After that, the rollers worked in unison to form the cylinder, and then the roller furthest away from the original material entry point performs the second prebend, bringing the cylinder to the desired form.
Without the need to remove the material from the machine, these machines developed a reputation for speedy work. Holloway said it’s the primary reason that the company now owns four DAVI four-roll plate rolling machines.
“You can type in the material, thickness, and radius [into the machine control], and the equipment will get you to a certain point, but every style of material has its own characteristics,” Holloway said. “But with this equipment, we can get close, which helps a lot.”
Two similar-looking plates of the same thickness might be distinctly different in the way they react in the plate roller. Plate with low-tensile and soft characteristics is likely to form as expected. Plate of the same thickness, but with high-tensile and relatively hard properties, is going to require different positioning of the bottom rollers to accommodate the material’s increased resistance to forming.
That continuing evolution of material performance has led Holloway Co. to invest in plate rolling equipment that can handle these more challenging metals. The current plate rolling equipment lineup includes:
The company routinely works with metals in the 1.25- to 1.5-in. range. While it doesn’t regularly work with material much thicker than that, Holloway said he was glad to add the DAVI MCB N30 plate roller because of its capacity.
“We might not roll a lot of 2-in. material, but it definitely gives us the ability to roll stronger 1.75-in. and 1.5-in. plate down to a tighter radius,” he said.
Again, the four-roll technology assists with these tougher materials because they are going to exhibit much more resistance to forming. The additional forming pressure, accompanied by the bottom rollers being able to be positioned strategically to apply that pressure, can battle the springback that often is seen with the high-tensile and hard materials.
The plate rolling equipment is relatively new, with the MCB 3045 plate rolling machine being the oldest and dating back to the early 2010s. Holloway said that contributes to the company’s ability to be responsive to its customers, both in terms of delivery and quality.
“When you’re doing custom plate rolling, you need to be able to get your product out as quickly as possible, or you’re not making any money,” he said.
Passion for plate rolling and fabrication keeps the focus on meeting customer expectations. Engaged and talented employees working with the latest plate rolling technology helps to keep that passion alive.