Shear makes cutting more exact for metal fabricators

Front supports help the operator to collect cut material when the stainless steel sheet stock is processed from the back of the shear. The front supports also help maintain accurate cuts by supporting the material during the shearing process.

A shear is one of the most important tools of the trade at JTC Metals. Steel Slitting Line Video

Shear makes cutting more exact for metal fabricators

The manufacturer and distributor of stainless steel products, such as backsplashes, wall trim, kick plates, shelving, and corner guards for residential and commercial kitchens and restaurants, prides itself on getting orders fabricated to exact customer specifications without marring the surface of the fabrications. The shear plays a very big role in helping accomplish that goal.

“A very large part of what we do is custom, so you don’t really know what someone's going to order until they order it,” said Rodney Wipf, a manager at JTC Metals. “That’s why it comes back down to the shear.”

When the company first started in 2013, JTC Metals worked with a 1980s-era shear. Years later, it upgraded to a more modern import that was “built with a hammer and a chisel,” according to Wipf. The shear cut the material, but the person operating the machine always approached it with a measure twice and cut once mentality because the machine didn’t provide the same precision offered by today’s CNC machine tools.

By 2019, Wipf and colleagues showed up at FABTECH in Chicago looking for a CNC shear that could help them improve their productivity without sacrificing quality. What they found was an exhibit floor filled with shears that looked like they operated like shears from a generation ago—and a lot of laser cutting machines. Wipf said that laser cutting machines definitely have their place in modern metal fabricating, but not necessarily at JTC Metals. The company produces a lot of straight-line cuts on stainless steel, and some of those parts, such as trim for joining, edging, and corners, can be pretty thin and thus a challenge for a powerful laser. With all that said, the JTC Metals team kept searching for a shear that would be the right fit for the shop.

A stop by the Boschert USA booth proved fruitful. The team liked the idea of a servo-electric shear that could be tailored for the company’s needs. The machine also was attractive because it uses 50% less power than a traditional hydraulic shear.

Conversations continued over the ensuing months but were interrupted by the pandemic. When a sense of normalcy returned to the manufacturing world, JTC Metals and Boschert USA technicians picked up the conversation. The Boschert Gizelis ElectroCut electric shear was delivered in late summer 2022.

Wipf said the ElectroCut is the right fit not only because of its critical standard features, but also because Boschert USA was able to customize the machine to further meet JTC Metals’ needs. As a result, this shear is quite different from the other machines that the fabricator had owned.

Specifically, the machine tool manufacturer created custom front supports for JTC Metals. Because so much of the fabricator’s work is highly visible when installed, the stainless steel workpieces can’t be marred. These custom extensions to the squaring arms and movable front supports help to prevent marks and dents on the valuable sheet metal material.

One of the most important standard features is a retractable 60-in. backgauge that allows JTC Metals to load up a 120-in. sheet and cut it in half accurately. That type of setup isn’t found on any of the shears that Wipf had previously looked at, and it really appealed to him given the way the shop works.

The backstop of the shear can retract 60 in. to accommodate large stainless steel sheets.

“It’s just the simplest setup for us to do,” he said.

The ElectroCut also has a feature for cutting narrow strip that fits the needs of a lot of JTC Metals’ work. The company cuts many narrow, stainless workpieces that, although small, are often very noticeable when finally installed. As a result, the cuts need to be exact and leave the sheared parts in pristine condition.

The shear’s material pneumatic hold-downs, which can be as close as 0.38 in. to the shearing blade, are key in this battle to cut quality narrow strips. Wipf said the company’s other shears had hold-downs located further away from where the blade engaged the metal, which necessitated frequent measurements to ensure the workpiece was the same width throughout.

The hold-downs close to the cut help to keep the material perfectly flat and in place. They also help to drive the internal material stresses found in the sheet back into the remaining sheet metal still being held in place, according to Jeff Snyder, Boschert USA’s sales manager.

“This creates near-perfect, smaller strips,” he said.

With stresses transferred back to the original workpiece, the last few thin strips that are cut from the sheet metal might demonstrate deformations, like curling, but Wipf said that’s much better than having to wrestle with each narrow strip that was cut using older shear technology.

The ElectroCut also features adjustable blade gap and rake angle that help to ensure all cuts meet original specifications.

“All of our machines can cut from 0.020 in. to the maximum rated thickness. That’s 0.25 in. in [JTC Metals’] range, and we can do every spot in between because our blade gap is actually driven by an eccentric drive,” said Snyder. “So, if you type the material thickness into the control as 0.125 in., the blade is going to a certain position. If you adjust the material thickness, say to 0.121 in., the blade is going to make a minor adjustment. Based on the information you give it, it’s going to make the right adjustment to get you the best cut that you can possibly have.”

Hydraulic shears need to be powered adequately to have the full force available throughout the entire cutting process. This means that each hydraulic cylinder of the shear needs to be sized to provide the full force of the cut on its own. It also means that the force provided on the shear blade is twice as much as needed in the center of the cut length. The end result is that the extra force comes with a sacrifice in ram speed.

That’s not the case with a servo-electric shear. The force is distributed where it is needed by means of a torque tube installed on top of the shear. This design leads to speedier movement of the ram during noncutting activities when compared to similarly sized hydraulic machines.

The servo-electric shear also costs less to run than a hydraulic shear. When hydraulics are removed from the machine design, many expenses related to energy usage and maintenance are eliminated as well.

The rake angle—the angle between the cutting edge of the shear and the plane of the workpiece—is determined automatically. The shear operator just needs to input the material thickness of the workpiece, and the shear sets the rake angle to achieve the specified cut.

Wipf added that the ElectroCut has a return-to-front feature that he has never seen available on a shear before. The material can be fed through the front and the cut pieces collected from the back like other shears. However, the servo-electric shear also works in the opposite direction.

“The backgauge and the sheet support system can work together to brace your workpiece, cut it, and push it to the operator so he doesn’t have to walk around the machine,” Snyder said.

Boschert USA offers a conveyor and stacking tool attached to the ElectroCut shear, and Wipf said that the company is considering swapping out its current shear for that setup in the future. JTC Metals doesn’t have a regular problem with sheared stainless steel parts dropping from the shear and marring the surface because one part edge fell just the right way onto another part, but it happens occasionally. Such a stacking tool would help in preventing the loss of that otherwise quality part.

“We’re always trying to improve, to expand, to look for more distributors, and to stay on top of trends,” Wipf said.