press brakes/tooling

Rolleri analyzed parts and press brake capacity to design/build tooling that could withstand tough materials.

Steel vs. machine
Tooling technology helps company bend abrasion-resistant steel while avoiding pitfalls like cracking

he W. L. French Excavating Corp. is used to pushing obstacles out of the way. The family-owned business based in North Billerica, Massachusetts, provides a wide range of construction services from mass excavation and soil management to site development, transportation, disposal and snow services. Its motto “We move Boston,” is fitting for a company that moves millions of cubic yards of earth annually, prizes its employees and is deeply embedded in its community. W. L. French needed an equally tough tooling solution to bend parts from Hardox 450 steel up to .50-in. thick using a 325-ton press brake.

Hardox is one of a number of alloys that have been designed to resist abrasion. These materials are in high demand for structural parts in industries like mining, agriculture and construction. Precision press brake tooling manufacturer Rolleri has studied AR steels and their applications since 2008 to help companies like W. L. French harness the advantages of these “super” metals.

Rolleri parts on table
Bending AR steels like Hardox requires a unique combination of knowledge and tooling.
Julio Alcacer, Rolleri USA
“Materials like Hardox allow a fabricator to use less material yet produce parts with the same structural force and a longer life cycle,” says Julio Alcacer, sales manager for Rolleri USA. “Those advantages are critical for a hopper or bucket on an excavator, for example.”

“The problem is that bending AR steels like Hardox requires a unique combination of knowledge and tooling,” he continues. “Hardox’s higher strength means it has greater capacity to absorb energy, but it’s also prone to cracking because of its lower ductility. You can only eliminate cracks by using a larger V-die opening. For 1-in. thick Hardox 450 plate, you need at least a 12-in.V-opening and a 14-in. opening when forming thicker plate. The same concept applies to the upper tool radius. The V-opening should be approximately 4 in. If it’s smaller the material will crack.”

W. L. French needed to bend parts from Hardox in thicknesses of 0.25 in. up to 0.5 in. “We were new to working with Hardox,” says W. L. French Welding and Fabrication Supervisor Mike Beaudoin. “We looked at several tooling manufacturers and quickly found out that not all tooling is alike. Rolleri had a firm grasp on the bending process and considerable manufacturing experience.”

Part analysis and evaluation of press brake capacity led Rolleri engineers to design/build a V-die with an 8.5-in. opening and a 70-degree angle. The die’s upper tool was engineered with a 2.25-in. radius and a 70-degree angle. Tool capacity was rated at 60 tons per ft.

View of Rolleri openings that allow W. L. French to bend Hardox steel without compromising part accuracy
Rolleri tailored V-die openings to allow W. L. French to bend Hardox steel without compromising part accuracy.
Springback was another challenge for W. L. French. Typically, press brake operators compensate for springback by overbending. Rolleri tailors its V-die openings with enough resistance to withstand the force generated by the press brake. The die allows the part to have a 15-degree to 20-degree springback without compromising part accuracy.

“Rolleri really educated us about the requirements needed to bend specific materials,” says Beaudoin. “We learned why this type of tooling requires special treatment to withstand the rigors of working with Hardox plate and how these materials react to the bending process.”

The custom made tools were installed at W. L. French’s maintenance facility in November 2020. “Inspection revealed the superior quality of the tooling,” says Beaudoin. “Their technicians helped make assembly of the package flawless. And we’re making the parts we need to keep our equipment moving.”

W. L. French Excavating Corp.,
Billerica, Massachusetts, 978/663-2623,
Rolleri USA,
Avon, Ohio, 440/835-2580,