Tough tools for ornery steel

Larry Bird vs. Magic Johnson – a rivalry that forced both players to play better throughout their careers. Muhammad Ali vs. Joe Frazier – three fights to decide which of the rivals could truly be considered the greatest. Steel vs. all takers – a fight that’s shaping the future of automotive and commercial truck production.

Like those great sports rivalries, competition is forcing steel to get better. In recent years, producers have come out with stronger, stiffer, corrosion-resistant alloys that allow vehicle producers to slash weight by using as little metal as possible without sacrificing safety or structural integrity.

There’s one big problem – that extra strength and stiffness makes cutting those bars, billets, and sheets into components a major pain for suppliers and job shops. For many producers, the tougher the material, the slower the cutting speeds, so making parts from the best alloys can lower production rates, hurting shop profitability.

Chad Miller, Seco Tools LLC’s product manager for turning and advanced materials, says toolmakers and insert companies have to develop new solutions to get cutting rates higher with tough materials.

“The steel companies have to design these advanced materials because vehicle makers are asking for stronger components that are structurally as sound as the heavier components they used to have in the vehicles,” Miller says. “If we don’t keep manufacturing and designing better inserts that last longer, and can machine these harder materials, we’ll be out of business.”

Designed to handle the tough materials, increasingly showing up on part specification orders, Seco has launched an updated line of Duratomic coated cutting inserts that can help shops regain some of the turning speeds lost to the harder steels.
 

Faster cuts, long tool life

TP0501, TP1501, and TP2501 inserts replace Seco’s TP0500, TP1500, and TP2500 Duratomic grades. In testing, manufacturers were able to raise cutting speeds, cut more components per insert, and improve quality – all while cutting ornery metals.

“Every year, the machinability ratings on these materials seem to be going down. The materials are getting more difficult to machine,” Miller explains. “That’s why we stay in business as a cutting tool company. If these materials were easy to machine, we wouldn’t be selling many inserts.”

Miller explains that different insert grades are meant for different applications.

• TP2501 universal steel insert – designed for job shops dealing with a larger variety of materials and parts.
  “They’re looking for an insert that they know will work when they put it on for different types of materials,” Miller adds.
• TP1501 harder insert for higher volumes – allows companies to increase speeds for a smaller number of products. The insert is more abrasive resistant than the TP2501, making it a better fit for rougher materials that need to be run at high speeds.
• TP0501 insert for toughest applications – supports long-duration, high-speed cutting of high-strengh steels.

“A lot of automotive companies and suppliers are machining with TP0501 for forged materials because the surface of the part might vary. The forged parts can have quite a range of surfaces and hardnesses, and a lot of times there’s a long time in cut,” Miller states. “With driveshafts or large pinions, we’re removing a lot of material, and we want to remove it quickly.”
 

Shinier surfaces

Users upgrading from first-generation Seco Duratomic inserts will notice one change immediately. The new inserts feature a shiny chrome finish. That extra bling, compared to the matte black surfaces from the first-generation Duratomic, isn’t just for show, Miller says. It’s a functional improvement so insert users can quickly identify which edges of an insert have been used.

“We’ve dug through that little cup next to the machine, the used inserts, and we’ll find inserts in there with only one used edge,” Miller says. “It’s not good for the customer. A lot of that comes down to education, but we feel that with the new chrome color, it will be much easier to identify which edges have been used. If you’ve got a four-edged insert, make sure there are four black spots on that insert to show you’ve used each edge. We know it’s never going to get to 100%. But, if we can get the customer to know what to look for, it’s an easy cost savings for them.”

Seco surveyed its customers and found that on average, companies that have full-time tool setters and crib attendants to handle insert changes still missed about 10% of the available cuttings surfaces, retiring tools before they were fully worn down. At shops where the people operating the tools are responsible for indexing and changing their own inserts, as much as 25% of inserts got swapped out too early. Miller says switching to a shinier, wear-evident coating for the inserts should make it easier to get the most out of every insert.

It’s a feature that Seco wanted in earlier versions of the Duratomic line, but the technology wasn’t ready, he adds.

“The old Duratomic, the aluminum oxide coating (Al2O3)that we had, if we did put a flash coating on it or a TiN coat, it would negatively affect the tool life. It wasn’t that we couldn’t put a coating on those inserts, but we chose not to, because we were more concerned with having longer tool life,” Miller explains. “With the advancements with our coating and texturing, our engineers came up with a very, very thin, PVD coating, a chrome coating, to put over the Duratomic. It doesn’t increase tool life at all, but it doesn’t hurt tool life this time.”
 

Higher speeds, tougher metal

Between the wear-evident coatings and the improvements in insert durability, Seco engineers believe that the new Duratomic line can give shops something that had been unattainable – high cutting speeds in difficult materials with cost savings from using every edge available.

“With the new steels, the specs on parts are getting tougher, but no one wants to take more time or slow down their machines, so we’re convinced that people are really going to need these new grades,” Miller says.

Seco Tools LLC
www.secotools.com

About the author: Robert Schoenberger is the editor of TMV and can be reached at 216.393.0271 or rschoenberger@gie.net.