MAKING THE CUT

Encounter tool steel and you'll find you need more of everything – more power, more performance, and, maybe most importantly, more knowledge.

Bruno Cecchini, the Plant Manager at Mecon Industries (Scarborough, ON), knows that tool steel grades are engineered for extreme levels of toughness and durability. In fact, he has known this for more than 45 years.

One of the original employees when Mecon opened its doors in 1962, Cecchini has seen Mecon develop two specialties – the manufacturing of coil-handling equipment such as coil reelers, unreelers, and coil straighteners for the metal fabricating industries, and press brake dies.

Press brake dies are tooling used for bending metals into predetermined shapes. Bending large or thick metal plate depends on the size of the die opening, the strength of the die, the shape of the punch, and the tonnage of the press brake.

"We design, manufacture, and test custom press brake tooling for bending any material thickness and material type, from steel and aluminum to exotics like Zircalloy," notes Cecchini. "Our planers range in length from 12 to 30 ft long. We also have a 200-ton hydraulic press for tryouts. With our experience, we can provide a single-hit tool that combines bends and reduces the number of hits to complete a part. We also stock a line of standard tools for off-the-shelf delivery."

Mecon customers can order the material type, thickness, and hardness of the dies they want to match the tonnage of their press brake equipment and the jobs they want to handle. If not otherwise specified, Mecon makes press brake tooling from pre-hardened die steel at 265 to 280 Brinell.

Recently, Mecon faced a significant challenge. A customer, Hodgson Custom Rolling (Niagara Falls, NY), required a die 14 feet long and 22 inches wide with an 18-inch die opening for bending two- to four-inch-thick plate. The die steel specified was so tough that the tooling Mecon traditionally used on its planing equipment lasted for only three strokes before failing.

Remember that dies are tooling used by customers to make the products their customers require, so when die customers say they need their tools, they're not fooling around. "We were really under the gun," remarks Cecchini. "We had promised a delivery date, and we had a 20,000 lb piece of steel at 35 Rockwell (which translates to 323 Brinell, well above Mecon's standard range) that we couldn't cut."

Normally, Mecon's planing machines are the workhorses of their die business, cutting at a maximum 200 ft per minute. Lowering speeds didn't help, the tooling they traditionally used was still failing after three strokes, and the range of tooling providers they sought help from "pretty much had the same results," in Cecchini's words, until Dan Atwell, a Metalworking Sales Engineer with Kennametal Inc. (Latrobe, PA), came to the Mecon plant with samples of the new Beyond? line of inserts.

This is a new line of tooling with a complete portfolio of new grades and geometries for cutting cast-iron, steel, stainless steel, and high-temperature alloys. This tooling is engineered to increase metal-removal rates and extend tool life, significantly in many cases. "Depending on the application," says Ujjwal Baid, Kennametal Senior Product Manager, "field tests have shown anywhere from 30 percent to 300 percent improvement."

Supporting these improved levels of performance are a number of technology features. The tools feature a new post-coat surface treatment that improves edge toughness, reliability, and depth-of-cut notch resistance, and micro-polishes the surface to reduce friction and workpiece sticking (BUE). A fine-grained alumina layer accommodates increases in cutting speed, improving productivity.

All the new inserts are CVD (chemical vapor deposition) coated, but where conventional CVD coatings are under tensile stress, these inserts undergo a proprietary post-coat treatment on all surfaces to reduce this stress, improving coating adhesion and reducing micro-chipping.

"More uniform and reliable wear of the cutting edge results in improved and more consistent tool life," explains Kent Mizgalski, Manager, Global Lathe Systems Engineering at Kennametal. "Smoother surfaces also lower frictional forces, another factor that expands applications and permits higher cutting speeds. Together with the right geometry, we've seen big improvements in chip control and tool life in both internal and field tests."

Atwell brought Mecon some samples of the new grade KCP40. "Dan brought in two inserts for us to try and we only needed to test one," quips Cecchini. "It kept us going."

According to Mecon machine operator David Filipovic, even on Mecon's standard brake die steel the inserts would last only 15 or 20 minutes per edge before failure. "We put this new grade on our planer mill and the final parameters we were running after the testing were 0.750 in depth of cut, 200 sfm, and .032 in feedrate," he says. "We were able to run 16 ft planer strokes for approximately 80 minutes an edge."

Getting approximately 500 strokes per corner and over five hours tool life per insert on 35 Rockwell tool steel was "unbelievable," says Cecchini. "The chips were nice and smooth. With five inserts, we were able to remove more than 4,000 lb of chips on this job." High praise, maybe the highest, when making money cutting tool steel is the situation you're facing.

Was Mecon able to deliver on time? "Without the use of these new cutting tools, we would have lost money on this job," answers Mecon president David Foscarini. "We invited other tooling suppliers back in to see how these tools cut. The only word for it was they were surprised."

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Kennametal Inc., 1600 Technology Way, Latrobe, PA 15650, 724-539-5000 www.kennametal.com.